Afterwards, walking alone in the hayfield (Dee and her new French friends were organizing a winter meeting in St. Bart’s), for the first time Rosalind saw the field not as a fan but as a funnel, gathering up and concentrating onto the vine-shaded porches the whole world of science, the elaborate structure of meetings and speeches and grants and reputations she’d assumed was her home.

NEAR THE END of the meeting, another storm, stronger and more destructive than the first one, passed through. The candles and kerosene lamps they used when the lights went out seemed romantic; less so not being able to wash, as the well pumps didn’t work without electricity. When they still lacked power the following night, Rosalind and Dee, along with her new French friends, Sebastian, and a few other young investigators, went down to the lake. They stripped, showing off in the moonlight, and hurled themselves into the water. Rosalind came up with streaks of mud on her arms, a stripe of blood running down one shin.

“Rock,” she said. “Underwater.”

Laughing as she said it. Dee tossed her a towel, and instead of covering herself, she whisked at her hair and then pressed the cloth to her bloody leg. Sebastian, who waded over to inspect the wound, said it was only a scratch and tossed the towel back to Dee before plastering Rosalind’s shin with warm mud. When she saw the older scientists, the ones who’d taught her generation, watching from the edge of the woods, she didn’t know enough to realize they might have done similar things when they were young. Some probably understood, as she did not, why she later left them.

I walked away from my first postdoc to do another in a completely different field, Marianne would write her afterwards. I lost a couple of years, but it was worth it. You could have taken a leave and then started over—maybe with a different problem, something new. You might have done valuable—really valuable—science for another twenty-five years. Instead—

Instead, some months after the conference ended and Rosalind and Sebastian split up (she’d known all along he was off to Alaska), Dee brought her the news of the caving accident. Rosalind had not thought about Sebastian much while she could still picture him working elsewhere. He might have traveled to another continent without letting her know, much as her sister used to do; he was somewhere working, that was fine. But now . . . for months after reading the obituary she continued on as if nothing had changed. Then, so swiftly and efficiently that even she was startled, she abandoned her lab in Chicago and the man who’d sent the postcard.