The cold air burned in her lungs. She recalled the emergency face mask in her backpack, and stopped and yanked off the backpack and dug, pulled off the CO₂ mask and put on the air mask; it contained a short supply of compressed oxygen in its frame, and with it pulled over her mouth and nose and turned on, she was suddenly stronger, faster, could hold a better pace. She ran along a strip of high ground between canyons, hoping to get a sighting of the rover round the slope of the crater apron. Ah, there it was! Panting triumphantly she sucked down the cool oxygen; it tasted lovely, but was not enough to stop her gasping. If she went down into the trough to her right it looked like it would run straight to the rover.

She glanced back and saw the polar bear running too, legs now in a shambling kind of gallop — lumbering — but it ate up the ground with that run, and the shallow canyon walls seemed no impediment to it, it flowed over them like a white nightmare, a thing beautiful and terrifying, the liquid flow of its muscles loose under thick yellow-tipped white fur. All this she saw in a single moment of the utmost clarity, everything in her field of vision distinct and acute and luminous, as if lit from within. Even running as hard as she could, focusing on the ground to make sure she didn’t trip over anything, she still saw the bear flowing over the red slope, like an afterimage. Pounding, running hard, boulder ballet; the bear was fast and the terrain nothing to it, but she too was an animal, she too had spent years in the back country of Mars, many more years in fact than this young bear, and she could run like an ibex over the terrain, from bedrock to boulder to sand to rubble, pushing hard but perfectly balanced, in control of the dash and running for her life. And besides the rover was near. Just up one last canyon side, and the slope of the apron, and there it was, she almost ran into it, stopped, reared up and pounded the curved metal side with a hard triumphant wham, as if it were the bear’s snout, and then with a second more controlled punch to the lock door console she was inside, inside, and the outer-lock door closed behind her.

She hurried upstairs to the driver’s aerie to look back. Through the glass she saw the polar bear below, inspecting her vehicle from a respectful distance. Out of dart-gun range, sniffing thoughtfully. Ann was sweating hard, still gasping hard for air, in and out, in and out — what violent paroxysms the rib cage could go through! And there she was, sitting safe in the driver’s seat! She only had to close her eyes and she saw again that heraldic image of the bear flowing over the rock; but open them and there the dashboard gleamed, bright and artificial and familiar. Ah so strange!

She was still in a kind of shock a couple of days later, able to see the polar bear if she closed her eyes and thought about it; distracted. By night the ice in the bay boomed and groaned, sometimes cracked explosively, so that she dreamed of the assault on Sheffield, groaning herself. By day she drove so carelessly that she had to put the rover on automatic pilot, instructing it to make its way along the shore of the crater bay.

While it rolled she wandered around the driver’s compartment, her mind racing. Out of control. Nothing to be done but laugh and endure it. Strike the walls, stare out the windows. The bear was gone but it wasn’t. She looked it up: Ursus maritimus, ocean bear; the Inuit called it Tomassuk, “the one who gives power.” It was like the landslide that had almost caught her in Melas Chasma, now a part of her life forever. Facing the landslide she had not moved a muscle; this time she had run like hell. Mars could kill her, no doubt it would kill her, but no big zoo creature from Earth was going to kill her, not if she could help it. Not that she was so enamored of life, far from it; but one should be free to choose one’s death. As she had chosen in the past, twice at least. But Simon and then Sax — like little brown bears — had snatched her death away from her. She still didn’t know what to make of that, how to feel about it. Her mind was racing so fast. She held on to the back of the driver’s seat. Finally she reached forward and punched Sax’s old First Hundred number on the rover’s screen keyboard, XY23, and waited for the AI to route the call to the shuttle returning Sax and the others to Mars; and after a while there he was, with his new face, staring into a screen.

“Why did you do it?” she shouted. “It’s my death to choose as I please!”

She waited for the message to reach him. Then it did and he jumped, the image of him jiggled. “Because — ” he said, and stopped.

Ann felt a chill. That was just what Simon had said, after he had pulled her back in out of the chaos. They never had a reason, only life’s idiot because.

Sax went on: “I didn’t want — it seemed like such a waste — what a surprise to hear from you. I’m glad.”

“To hell with that,” Ann said.

She was about to cut the connection when he started speaking again — they were in simultaneous transmission now, alternating messages, “It was so I could talk to you, Ann. I mean it was for myself — I didn’t want to be missing you. I wanted you to forgive me. I wanted to argue with you more and — and make you see why I’ve done what I’ve done.”

His chatter stopped as abruptly as it had started, and then he looked confused, even frightened. Perhaps he had just heard “To hell with that.” She could scare him, no doubt of that.

“What crap,” she said.

After a while: “Yes. Um — how are you doing? You look…”

She cut the connection. I just outran a polar bear! She shouted in her mind. I was almost eaten by your stupid games!

No. She wouldn’t tell him. The meddler. He had needed a good referee for his submissions to The Metajournal of Martian History, that was what it came down to. Making sure his science was properly peer-reviewed — for that he would crash around in a person’s most inward desires, in her essential freedom to choose life or death, to be a free human being!

At least he hadn’t tried to lie about it.

And — well — here she was. Rage; remorse without cause; inexplicable anguish; a strangely painful exhilaration: all this filled her at once. The limbic system, vibrating madly, spiking every thought with contradictory wild emotions, disconnected from the thoughts’ content: Sax had saved her, she hated him, she felt a fierce joy, Kasei was dead, Peter wasn’t, no bear could kill her, etc. — on and on and on. Oh so strange!

She spotted a little green rover, perched on a bluff over the ice bay. Impulsively she took over the wheel and drove up to it. A little face peered out at her; she waved through the windshields at it. Black eyes — spectacles — bald. Like her stepfather. She parked her rover next to his. The man gestured for her to come over, holding up a wooden spoon. He looked vague, only half pulled out of his own thoughts.

Ann put on a down jacket and went through the lock doors and walked between the cars, feeling the shock of the frigid air like a dousing in cold water. It was nice to be able to walk between one rover and another without suiting up, or, to get to the crux of the matter, risking death. Amazing that more people hadn’t been killed by carelessness or lock malfunction. Some had been, of course. Scores, probably, if you added them all up. Now it was just a dash of cold air.

The bald man opened his inner-lock door. “Hello,” he said, and offered a hand. “Hello,” Ann said, and shook it. “I’m Ann.” “I’m Harry. Harry Whitebook.” “Ah. I’ve heard of you. You design animals.” He smiled gently. “Yes.” No shame; no defensiveness. “I was just chased by one of your polar bears.” “Were you!” His eyes opened round. “Those are fast!”

“So they are. But they’re not just polar bears, are they.”

“They’ve got some grizzly genes, for altitude. But mostly it’s just Ursus maritimus. They’re very tough creatures.”