She was curious about his house—and his wife, Anita, a pretty, dark-haired woman of thirty or so she’d met only once in passing—but of course lab assistants didn’t get invited to Sunday dinner or to socialize or sit around dipping croutons into the fondue in the bosom of the family, and in any case, Bottmingen wasn’t exactly in the heart of town. The odd thing was that she hardly noticed the place when they finally arrived—it was a house and he lived there and that was all that mattered. She was sweating, exhausted, her heart about to burst through her chest, but she followed his lead, making a sharp right turn and pedaling up the gravel drive to the front of the house, where he just dropped his bicycle on the lawn and bolted inside, leaving the door wide open behind him, the keys dangling in the lock. Even as she propped her own bike against the tree in the front yard, wondering if she should follow him in and explain the situation to his wife as best she could, she heard him shouting within. “Anita! Anita, where are you?” There was a clatter, as of something metallic crashing to the floor, then a silence. A beat. Two beats. And then a long drawn-out moan of despair: “Anita!”

Tentatively, she made her way up the steps and into the front hall. The sun was out still but it was shadowy inside, none of the lamps lit and the light from the yard held trembling in the windows. “Herr Hofmann?” she called, afraid to enter uninvited.

His voice cracked as he cried out his wife’s name one more time, and then it dropped almost to a whisper: “I’m here,” he said. “In here.”

She found him in the sitting room—sofa, chairs, end table, lamps, everything in perfect order—staring wildly about him. “She’s . . . she’s gone,” he said, and all the breath went out of him.

“Gone? What do you mean?” It was nearly six in the evening—any wife, let alone the wife of such a man, would have been at home, cooking the meal, looking after the children, there to greet her husband at the end of a long day.

“Gone,” he repeated. He pressed his hands to his temples, as if the internal pressure were too much to bear. “And I’m left here dying, I tell you, dying. I’m poisoned, can’t you see—?”

That froze her inside—could it be true? Was it fatal? Had he miscalculated the dose? None of the dogs had died, had they? But then who knew what effect an experimental drug might have, a new drug, one nobody had ever tested before on a human subject?