“Thank you for that update.” Milton stared into his own lap for a moment. Then he looked up, in every direction at once. “There’s been a wrinkle. Earnest Mather has been running some numbers, and he has a … let’s say a concern. Earnest, can you share your findings with the group?”

“Umm.” Mather looked as though he’d been through a lot since Laurence dropped out of the sky and bought his company. He’d cut off his exuberantly frizzy hair and started wearing chunky engineer glasses. His shoulders were permanently hunched as he sat on a stool. “I have done the math about two thousand times, and there’s, well, a possibility. Let’s put it between ten percent and twenty percent. A possibility that if we turn this machine on, we’ll start a reaction that would lead to an antigravity cascade, which in turn could tear the Earth apart.”

“But tell them the good news,” Milton said quickly.

“The good news? Yes. The good news.” Earnest did his best to sit up straight. “First, we would probably have about a week, between turning the machine on and the Earth being obliterated. So, with efficient crowd control, we could get a lot of people through the gateway before Earth was gone. And there’s around a fifty percent chance that if the destructive reaction started, we could stop it by turning the machine off.”

“So,” said Milton. “Let’s say it’s a ten percent chance of the destructive reaction starting, and a fifty-fifty chance that we could avert a catastrophic outcome in that case. In fact, it might only be a five percent chance of planetary rupture. Or a ninety-five percent chance that everything would be fine. So, let’s discuss.”

Laurence felt like he’d jumped off that high gantry, instead of taking the elevator. He wondered if he should have found a way to warn more people about what happened to Priya. Everybody was trying to talk at once, but all Laurence could make out was Sougata’s cursing. Laurence looked at Isobel, whose folding chair wobbled as she hugged herself, and he wouldn’t swear she wasn’t crying. With no windows and the door sealed tight, the room seemed even more airless than it had before, and Laurence had an irrational panic that he would step outside this room and find the whole outside world erased, gone for good.

Earnest Mather was weeping into a wad of paper towels, even though he alone had known about this bombshell in advance. Maybe because he’d been processing the information for longer, he was readier to cry over it. Laurence couldn’t believe it was going to end like this. How was he going to keep Isobel from falling to pieces?