He had zero intention of not getting in touch with her again. A drowning man didn’t push away the spar he’d just grabbed, did he? Not likely! What she’d do then… Again, he could only wait and see. And if she didn’t decide he was too strange to deal with, he could only wait and see how they got along, or if they got along at all.

For now, Kelly said, “You’ll want to do some more exploring, and after the quake I really need to check that seismograph. I got more data than I thought I would.” As if to underline her words, another little aftershock rattled the boardwalk.

What Colin wanted to do was hang around right here and get to know her as well as he could as fast as he could. But he saw she’d given him a test question. Between the lines, it said If you come on too strong, you blow it. If he couldn’t work that out, he flunked.

So he said, “Sure. Glad to meet you,” and went on his way. He drove up to Dunraven Pass, which he might have done anyway, and looked south across miles and miles (more than thirty of those miles, he later figured out) to the distant mountains on the far side of the caldera (the middle-sized caldera, he reminded himself). Then he left the park altogether, which he wouldn’t have done if he hadn’t talked to Kelly Birnbaum.

He drove into the town of West Yellowstone, up US 191 to US 287, and west on 287 to Hebgen Lake and on to Quake Lake. The visitors’ center there perched high on the debris that had slid down from the far side of the Madison River and dammed it after the 1959 temblor. The rangers at the center seemed impressed he’d ever heard of the quake. They didn’t worry about the supervolcano. Maybe it was too big to worry about. Hoping the world stayed lucky seemed a better way to go.