Unbidden, I remembered walking at night once with Stefan, a friend who was a vampire. At one point, he stopped, looked up at the moon, and said, totally out of the blue, “I miss the sun.” And the last word sounded as though it had been dragged up from the depths of his being. If someone asked Stefan what he would wish for, I think that the ability to walk in sunlight would be very high on that list.

Could Thomas walk in the sun?

As soon as I thought that, terror screamed up my backbone. Vampires are evil. Even though I like some of them, I know that they are evil. Symbols of faith can work against them, repel them and cause them pain. Wood works against vampires because it was something that once was living that became dead—sympathetic magic of a sort. But it is sunshine that is the real weapon against vampires.

“Mercy?” Margaret said, her voice concerned.

That was a secret too dangerous for anyone to have. They would hunt him down. Which they? All of “they.” Vampires would hunt him down to steal his secret. Everyone else would hunt him down to kill him to get rid of the fear I had coiled in my stomach.

“Don’t ask him,” I said, my voice hoarse. “This gift from your power, I think I know what it was.” Thomas called her Sunshine, I remembered. “That’s a secret too big for acquaintances, no matter how friendly. When we’re friends, we can pretend you told me then. For now we can say that I have an idea—and I’m going to pretend I’m wrong because that would make Thomas the scariest vampire I’ve ever heard of.”

We drove for a few miles in silence.

Then she said, “Thomas isn’t a monster—though he’d disagree with me on that. I don’t know how he managed it, with his father, who was the single coldest being I have ever known, but he’s a good man.”

I nodded, though I wasn’t as sure of it as she was. I cleared my throat. “So the third thing you gave him was your blood.”

“It sealed the bargain,” she said. “That’s what my father said. For the next seventeen years, I always knew where he was, whether he was . . . well, not happy. Thomas doesn’t do happy very much. But he was content. Or if he was unhappy or cold or whatever . . . He says that he did not feel the same connection—not the same way.”