His knuckles rapped the frame. “What’s missing? They’re all there. Callum, Moshi, Henry, Alana, Raina. The whole team.”

“Yes? So?”

“So who took the picture?”

—

It took half an hour, and a lot of shouted insults, but by then Donbul was simply going through the motions. Callum could see doubts troubling the man, that just because he’d come through wearing a guard’s uniform, that didn’t actually make him a guard. That and hope. A way out.

Callum strapped the guard uniform belt around his coat, checked the weapons, and cut the pair of them loose. He stood back, one hand very close to the pistol holster. “Just so we understand each other, I don’t trust you. So keep your distance and no fast moves. I’ve sacrificed everything to come here. Shooting you won’t even register.”

Foluwakemi stretched and rubbed her wrists. Donbul simply glared at him and went over to the drums to find himself new trousers and boots.

Now that the daylight had strengthened, Callum could see the lake was actually a rough circle a couple of hundred meters in diameter. Sitting on the rock shelf just out of the water was a raft made entirely of the yellow drums lashed together.

“It’s a volcanic caldera,” Foluwakemi said, watching him. “There’s a group of them in this section of the canyon. Without them, we’d be dead. They supply all our heat and water.”

Callum glanced up at the phenomenal walls of rock. “And the air? Do they vent that as well?”

“Only sulfur gas. We’re seven kilometers below the planet’s average ground level. That’s why we have air. It’s a tiny pocket, the last on Zagreus. It must have had a full terrestrial atmosphere at one time, maybe a million years ago. But now it’s as thin as Mars, that’s why no one bothered to try and terraform it. You’d have to import a whole new atmosphere. Too expensive, especially when exoworld astronomy has found so many worlds with a nitrogen-based atmosphere close by.”

“How long’s the canyon?”

“Three hundred kilometers, we think. A few of us remember the Orion survey images and news reports. But less than twenty percent is habitable, and this is the only cluster of geothermal vents.”

Callum squinted up into the sky. It had brightened to an astonishingly deep sapphire blue. “Where’s the portal?”

“It’s on some kind of drone blimp, we think,” Donbul said. “They lower it when they’re sending a batch of people through—which only happens at night, so we can’t ever see it. That way we can’t jump on board and go back through the portal. The rest of the time it stays up there somewhere, all nice and safe from us badboys.”

“Makes sense,” Callum muttered. “So it won’t come down again until tonight?”

“Never has,” Foluwakemi said. “But then we’ve never had anyone like you come through before, either.”

“It’ll take security a while to work out what’s happened. As soon as they do, they’ll round my crew up and send them through along with Dimon and Akkar.”