"I want to buy a gun," said the Thymomenoraptor. He moved his foreclaw along the glass case of pistols, counting them off: one, two, three, four. "That one." He tapped the case; the glass squeaked.

"Why would a dinosaur need a gun?" asked the shop owner.

"Self-defense."

The owner's gaze dropped to the three-inch claw that had chipped his display case.

"These are killing claws," said the dinosaur, whose name was Tark. "For sheep, or cows. I merely want to disable an attacker with a precision shot to the leg or other uh, limbal region."

"Uh-huh," the owner said. "Or maybe you figure humans shoot each other all the time, but if someone turns up ripped in half the cops are gonna start lookin' for dinosaurs."

Tark carefully pounded the counter. "There used to be a time," he said, "when gun dealers would actually sell people guns! A time . . . called America. I miss that time."

"I don't sell to foreign nationals."

"Racist!" The gun dealer flinched but said nothing. "All right, look, just give me this periodical, okay?"

"I got ripped off," said Tark a little later. "That periodical contained neither guns nor ammo."

"Well, I'm not buying the self-defense idea, either," said his friend, a pachycephalosaur named Entippa. They walked their bikes onto the motocross track on the periphery of the packed-dirt arena. The screaming crowd surrounded them like a bowl. "What's the real story?"

"Humans won't pay to watch dinosaurs ride motocross bikes forever," said Tark. "I'm gonna branch out. Target shooting. I'll be like those tough guys in the action movies. Is my chin strap tight?"

"It's fine," said Entippa. The dinosaurs straddled their bikes. "What movies are you talking about? Like the Rogue Raptor schlock? I admit that giving Rahnarsh a gun would help the camp value somewhat—"

The starter's pistol went off and the two dinosaurs hit their throttles. They rocketed ahead of the pack and shot up the first of a series of packed dirt ramps.

"I'm talking about the humans!" shouted Tark. "Vin Diesel, your Bruce Willis. Your Hulk Hogan, going back a few years."

"You gonna dress up in a little camo outfit?" said Entippa. "That's chimp work, dude."

Tark hit the ground in a slide that left his tail an inch above ground. His feathers sucked up mud. "I pictured something very tasteful," he said, "with some cows in a meadow, and then I shoot them."

Entippa and Tark hit a bumpy patch near the school bus jump, and crisscrossed each other in a series of short shuddering hops that contorted their bodies above their bikes. "I can't hear you!" said Entippa, but Tark couldn't hear him either.

They got on the local news.

INTERVIEWER: Nice racing.

DINOSAUR RACER 1: Thanks.

INTERVIEWER: Where you boys from?

DINOSAUR RACER 1: Atlantis.

INTERVIEWER: I thought your people came from Mars.

DINOSAUR RACER 2: The Atlantis basin, yes, on Mars.

INTERVIEWER: What brings you to Tampa?

DINOSAUR RACER 1: We came to do high-speed stunts in double gravity.

INTERVIEWER: So how do you like Earth?

DINOSAUR RACER 1: Well, it's not as awesome as Mars—

DINOSAUR RACER 2: My friend means to say that Earth is very awesome, but sometimes we get homesick.

INTERVIEWER: How intelligent are dinosaurs?

DINOSAUR RACER 2: We're probably not going to win any prizes, but if you think about it, neither are you.

Post-interview, they sat in the stands enjoying Big Gulp cups of beer. Tanker trucks sprayed down the dirt and the flies. The dinosaurs' hearts beat quickly in the Florida night.

"It's a slippery slope," said Entippa. "You start carrying around a weapon and you become a cartoon character in the eyes of the humans. They'll strip you to the bone and then they'll put your bones in a museum. We stick to the basics. We're bigger, we go faster, we go higher, we hit harder."

"Sounds like you want Dino Fights," said Tark. He brushed an Earth insect out of his feathers.

"Dino Fights is repulsive. Whoever does those should be locked up."

"It's totally fake. Like pro wrestling."

"Totally repulsive. Now, if we stick to the traditional Martian demonstrations of prowess, there's still—is that a blimp? Do humans have blimps?"

It would seem they had. The blimp rose like a drunken moon above the stadium, straining to keep its cargo clear of the bleachers. Strapped beneath the blimp was what looked like a whole junkyard.

"LADIES AND GENTLEMEN, BRACE YOURSELVES FOR THE LARGEST LAND VEHICLE EVER CONSTRUCTED!" The announcer's voice originated from the sunnier suburbs of Hell.

The flying junkyard was a truck. One of its titanium-rubber wheels grazed a stadium light. Metal and hot glass rained down on some unfortunates in the cheap seats.

"That's what I'm talking about!" said Tark. "I bet they'll have that thing jump over other, smaller monster trucks!"

"THIS IS NO JOKE, NO HOAX! THIS IS THE GRIM REALITY OF THE JET-POWERED DESTRUCTORAPTOR!"

"Destructoraptor!" said Entippa. "Give me a break! Why don't they just call the damned thing Truckasaurus?"

"Because there already is a Truckasaurus," said Tark. "A modified steam shovel."

"THREE TURBINE ENGINES! THIRTY THOUSAND POUNDS OF THRUST! HUNDREDS OF GALLONS TO THE MILE!"

Ropes were cut and the truck hit the ground and bounced, sending a shock wave through the bleachers. Freed of Destructoraptor's weight, the blimp shot upwards and vanished beyond the edge of the stadium.

"A TRUCK SO ENORMOUS IT COULD ONLY BE DRIVEN BY . . . REX!"

A tyrannosaur came charging into the arena like an entire football team in one body. Dust clouds bloomed beneath her feet in places the tanker trucks had missed.

"And why is every carnosaur 'Rex'?" said Entippa. "It's like calling a human 'Erectus.'"

"Hey! It's Cass!" Tark stood up and waved, spilling his beer. "Yo, Cass!" He turned to the agitated humans in the row behind him, who probably wished they'd been under the broken light. "She's the best!" he yelled for their edification. "She's in movies!"

Near the truck, Cass took up dominance posture and screamed. Ropes of saliva arced from her gums, bearing huge chunks of meat and blood. Entippa covered his eyes. "She's gone rogue!"

"That's McDonald's cheeseburgers, ya baby. She's carning out. The humans love it. Go, Cass!"

"NOTHING . . . CAN PREPARE YOU FOR WHAT YOU ARE ABOUT TO WITNESS." That shut the crowd up for a couple seconds.

Cass threw open Destructoraptor's driver's-side door like a child already bored with her birthday present, and stormed into the cab. She settled her tail into a plate-armored tailpiece protruding from the back of the truck. The tail thrashed, taking out the windows of a few junkers, and then the three turbine engines came to life.

The crowd made itself heard over the turbines as Destructoraptor picked up speed. The front wheels shuddered back and forth, shaking the huge machine.

"Oh, no, no, no," said Entippa.

The truck made a wide turn on the roofs of some burned-out stock cars and cut across the motocross track, wobbling towards the side of the arena that hadn't yet gotten a good look.

"Tark, I don't think Cass knows how to drive!"

Most things in the arena were too small to pose a threat to Cass. The poles marking the motocross track's finish line went down and took the Pepsi banner with them. A portable ramp was crushed for easy storage. Even a utility bulldozer hardly slowed Destructoraptor.

It was the school bus jump that did it, laid out in no-man's-land in the middle of the arena. The first bus was no more trouble than the bulldozer, but there were six end-on-end and the third one hit the truck's undercarriage with an uppercut and sent Destructoraptor crashing onto its side.

The announcer's voice drowned in feedback. One of Destructoraptor's engines sucked in a mouthful of dirt and bus parts, and stalled out in a toxic cloud. The other two pushed Destructoraptor like a knife along the row of buses. Firefighters and paramedics rushed into the arena and steeled themselves to face the monster down.

Humans come to events like these and scream themselves hoarse. They scream all night from excitement and because everyone else is screaming. But if something terrible happens while they're screaming, they stop. They need to change gears before screaming can be terrible again.

But Cass was screaming, braking with her tail, slamming her side against the passenger side doorframe. Tark and Entippa were screaming, running towards the skidding machine at umpty-ump distance per Earth time unit: not wanting Cass to die, not here on the planet her ancestors had escaped.

The emergency workers stayed quiet, efficient as robots, teeming around the huge dead machine with their hoses and Jaws of Life, as if they had been expecting this. And they hadn't been, but they'd tell each other later, at the bar: maybe it's wrong to even say this, but what did you expect? What did they think would happen?

Spark plugs don't care. No matter what, they need to be checked, and Entippa was checking them. He yawned comfortably in the baking parking lot. The door to their motel room was propped open and inside he could hear Tark cursing at the Internet. There was no rush to see Cass in the hospital. Normal visiting hours don't apply when the patient's lying in traction on the hospital lawn.

Two young humans in sandals observed Entippa, safely out of range of his tail. They differed in sex, but Entippa couldn't tell which was the male and which the female.

"Do you know Stegosaurus?" asked one of the children.

"Stegosaurus is a whole genus," said Entippa, "not a person."

"Oh! Triceratops! Do you know Triceratops?"

"Triceratops died out when your ancestors were tree shrews," said Entippa. He turned over the spark plug, looking for cracks. "The chasmosaurs were the only ceratopsians who made it to Mars. And then they split into the alethinosaurs and the bradupeithids." He set the spark plug down on the motel towel.

"I found it!" shouted Tark, stumbling out of the motel room. The children goggled.

"What kind are you?" asked one.

"Kick-your-ass-a-saurus. Hey, how would you kids like to see a real tyrannosaur?"

"Are you trying to scar these kids for life? Real third-degree burns! Her tail's broken in five places!"

"Don't guilt me! I love Cass like my sister who's a different species for some reason. My half-sister. So, I'm putting in the legwork to find out who's behind this. I did a web search for 'I hate dinosaurs' and it's either the radical birdwatchers or the young-earth creationists."

"I'll tell you who's behind it," said Entippa. "Some idiot built an unsafe vehicle and another idiot named Cass signed off on it. She's got carnosaur entitlement syndrome. People get hurt and everyone says 'Oh, how could this have happened' and it happened because carnosaurs think they own the world."

"You're neglecting the important point, which is, birdwatchers."

"Birdwatchers."

"I never realized the depths of their hate, Entippa. One faction that considers us birds, fit only to be watched. And another faction that considers us mere lizards, beneath their notice!"

"I'm not feelin' the hate, to be honest."

"Here's the scary part. They're having a meeting to resolve this issue one way or the other, this weekend, in Boca Raton. The same week the Reverend Doctor Billy Fitch comes to town with his big tent and his footprint casts that prove Jesus walked with Dimetrodon. So what do you think? Pretty good detective work, huh?"

"You've proved nothing except that Florida is full of crackpots."

"Do you hear a helicopter?" asked Tark, and crumpled. "Ow! Something bit me!"

"You got shot by a bunch of goddamn poison darts! They're all over your leg!"

"They're trying to silence me! Entippa, carry on my work!" Tark fainted with his tongue out. There was definitely a helicopter coming towards the parking lot. It was camo green, but not military.

"Get out of here," Entippa told the kids. He swung onto his bike, which wouldn't start. Spark plugs, right. A second frill of darts hit him in the stomach. Fingers of nothingness burned outwards from the punctures. Entippa fell wobbly onto Tark, the bike skidding away.

"Are you okay?" said one of the kids, already climbing all over Entippa the way kids always wanted to.

"Stop it!" said Entippa. There was a puff of gas from the helicopter and a net bloomed around them. The kids screamed.

"Tark! We're being kidnapped! Wake up! Bite through this net or something!"

"Not . . . made of biting," Tark muttered, but Entippa was already asleep.

A light flicked on. Tark woke up.

"It's about time," said a voice. "I've been flicking that light on and off for ten minutes."

Tark sprawled, immobilized, on a concrete floor. The light was one of many hung from a tall ceiling. The walls bore a gradient of dark red stains that faded out three meters up. Some ways away Entippa lay on his side, snoring loudly.

"Hey, I know this place," said Tark.

"Then you're a fan of Dino Fights?"

Tark's eyes darted back and forth. He couldn't see an exit. The voice came from behind him.

"Not as such," said Tark, "no."

"That's a shame," said the voice. It came closer; Tark heard someone climbing down a ladder. "It's more fun to shoot with fans. Makes a better show."

"I'm not fighting my best friend. Entippa! Help! Wake up!" Entippa blinked but didn't move.

"Why not? You've got your claws, he's got that battering ram of a skull. It's a fair fight."

"The skull dome is not a weapon," snapped Entippa. "It's used only in mating rituals and dominance display." He resumed snoring.

"What he said. Also, you're insane!"

"It always comes down to that, doesn't it?" said the voice in disgust, now circling around Tark. "Whether a successful Internet filmmaker can also be insane. Given that his quote-unquote insanity is also the fuel for his objectively measurable success as an entrepreneur. And whether it makes sense to judge him by the standards of talking dinosaurs from Mars."

"We have people like you," said Tark, "they're just crazy."

"Crazy, for creating a space where dinosaurs can do what they've always wanted to do, that being kill each other? Au contraire, my reptilian friend." The voice came into Tark's field of vision. It was just a human in a T-shirt. Tark snapped at him helplessly.

"The Greeks had a word for it. The source of ideas that become profitable subscription-based websites. They called it the genius. That's the word I prefer. And once my handlers get here and the extremity paralysis wears off, you will fight your friend. You'll probably even enjoy it."

The human looked down at Tark. "I always wondered what color the feathers were," he said. "Back in Cretaceous times. I imagined corn-syrup Toucan Sam colors. But you're brown. Brown, black, or dark orange, or in your case grey. You're a pigeon, my friend."

"Entippaaaa!" called Tark. "He's mocking my plumage!"

The human kept walking, completing his circuit of Tark. "But what a pigeon! A war pigeon. Nature red in tooth and claw. A sculpture in power." Tark felt a clammy hand gently stroke his flank.

"Don't touch me," he said, and kicked out with both feet.

Tark's foot caught something and sliced it. The human let out a cry and stumbled backwards. Something spilled onto the concrete and a body hit the ground. The human let out a long, long groan, and then there was no sound but Entippa's snoring.

"Damn," said Tark, "that smells really good, and I haven't eaten today." He waggled his arms and they waggled back.

"Entippa," Tark called softly, "if you don't think I should eat this guy, then say so right now." Entippa said nothing.

"Sounds like a plan." Tark got up and turned around. His knees gave way and he fell into a split. He ate the guy from a sitting position.

"Are you eating that guy?" asked Entippa later as Tark rounded the room on shaky legs.

"Already taken care of, buddy," said Tark.

"Do you ever think? We're in the shit now. You literally killed a guy and ate him. You've confirmed the worst dinosaur stereotype imaginable. There will be riots in the streets."

"He was going to make us fight to the death!" said Tark. "I made an executive decision."

"To kill him. And then you made a different decision to eat him and snap his bones and I don't know what you meat-eaters do. We are so—" Entippa's head dropped back to the floor.

He woke up when Tark dropped a refrigerator into the arena. The refrigerator buckled on impact. Its door burst open and tiny cans scattered across the floor like cockroaches.

"Have some Red Bull," said Tark. "I drink it to counteract the tranqs." Tark climbed down the ladder. EMPLOYEES was stenciled on the refrigerator door.

"You drink Red Bull all the time," said Entippa.

"Yeah," said Tark. "It's 'cause I've been taking tranqs to help me sleep. Those motel blankets are real scratchy. I guess you build up a tolerance if you take a lot." Tark flexed. "Uh, I guess you're going to lecture me about this, too." But Entippa was asleep.

When Entippa came to again he was drowning because Tark was pouring Red Bull down his throat. Tark walked Entippa around the arena until feeling came back into his legs.

"Man, if I had a gun?" said Tark, "I'd have really taken care of that guy."

"You did take care of him! With your foot!"

Tark had even filled the freezer compartment with wilted, half-frozen greens, which Entippa devoured. "There's this walk-in freezer that says LIVESTOCK," Tark said. "It's got more if you want."

Entippa climbed the ladder. The rungs bent as he stepped on them. At the top, near a bank of camera controls, stood the kids from the motel parking lot, holding each other and quaking.

"Where'd you find them?" asked Entippa.

"The kids," said Tark, "were also in the freezer."

"The LIVESTOCK one," said Entippa. "Okay, these kids are our ticket out of here. We need to call the police. Where do you humans keep your phones?" The kids said nothing.

"Actually," said Tark, "I bet that guy left his car parked outside."

"I guess we won't all fit in that car," said Tark.

"The kids will fit," said Entippa. "Do you kids drive?" They eventually shook their heads. "Probably too young."

"It's pretty big," said Tark. "Let's just take the top off. I'll drive."

"You don't know how," said Entippa. "You'll crash and kill us all."

"Motocross bike is the same as a car," said Tark. "Let's try it." The two dinosaurs smashed in the windshield and peeled back the roof of the car.

"Kid number one," said Tark, "I need you for detail work. Here's the keys. Put these in the ignition. Sorry about the blood." The kid started crying.

"Someone's coming," said Entippa, looking over his shoulder. "Probably the handlers."

"You have to stop crying and get in there!" said Tark, gesturing. "Crying is not productive! I said it's not productive!"

"That's not how you talk to kids! It's too late now. Let's get them to cover and do the phone idea."

"You do that," said Tark, and ran down the road towards the car that held the handlers.

"Okay, kids," said Entippa. They looked at him with big eyes. "Dammit. Get on my back. I'll give you a ride." He dropped to his knees and nearly fell asleep again. Somewhere Tark shouted, "I ate your boss!"

Entippa crawled back to the entrance of the nondescript commercial building. His waking dream filled with screams and gunfire. He turned a corner and collapsed. The kids stroked the spikes on his temples and he didn't care.

Several humans ran past him, falling and scrambling on their hands and knees. Entippa heard a car pull up on rapidly deteriorating shocks. He looked up to see Tark's feet sticking out of the windshield cavity.

"Entippa!" said Tark. "I got it! I got a gun! Check it out!" There was a shot and the sun roof dissolved. "Ow, there's glass! Stupid gun!" Tark hurled the gun out the driver's side window and into a bush.

Entippa sucked in air and pushed himself up. The kids got into the back seat. Entippa climbed onto the back of the vehicle and all four tires went flat.

"Okay, the whole car idea is stupid," said Tark.

Their lawyer was a human, of course.

"Well," he said, "the self-defense angle is pretty strong against the murder charge. But there's also the cannibalism—"

"How can it be cannibalism for a dinosaur to eat a human?" asked Tark. "Hypothetically speaking, I mean."

"—brandishing, assault with a deadly weapon"—(Tark looked down at his claws, clipped to stumps)—"destruction of property, unlicensed possession of Red Bull in excess of five liters, cetera cetera. But given what was going on in there, and the fact that you saved those kids, I can't say you're in the worst shape of any clients I've had."

"Jail sucks," said Entippa. "I want out."

"The cell hasn't been built that can hold me!" said Tark. "Although they did tear out the wall between two adjoining cells."

"Unfortunately, it keeps coming back to the alleged cannibalism. That's just not something that the state of Florida can wink at, except in certain special circumstances which are not met here."

"I was allegedly very hungry," said Tark.

The door cracked open and a tubby ornithoraptor poked his head in.

"Excuse me," said the lawyer, and left the room.

"First they call you a hero, and then they arrest you for allegedly eating a guy," said Tark. "I can't believe we share a common ancestor with these bozos."

"I hope you're happy."

"Well, I'm not!"

The lawyer came back in. "I'd say good news," he said, "but that's for you to decide. The embassy has gotten involved. You boys are going back to Mars."

Tark slowly moved his head forward, trying to keep the diminishing Earth from disappearing off the edge of the porthole.

"That's annoying," said Entippa. Tark sat back down on his lounge stool.

"I wish we'd found out who did that to Cass," he said. Entippa leaned sideways to bang his head against the hull.

"Does it hurt when you do that?"

"We set her up," said Entippa, "when we came to Earth. We saw how humans revered our ancestors' skeletons and we thought they'd want to see the real thing. But they don't. They don't want us or even the ancestors. They want what we've become in their mythology. They want the dark part of themselves, and they want to be able to punish us for showing it to them."

Eventually Tark said: "I wanted to jump the Grand Canyon."

"There's the Valles Marineris."

"Yeah, but the gravity's less."

Sitting on the other side of the porthole, Entippa could still see Earth, sliding into the past. He gnawed his lip like a stick of bamboo.

"Chimp work," he said to himself. "It's all chimp work."