"Agent Morse," he said in a neutral tone, "I'm not going to discuss my wife with you. But I will tell you this. Thora doesn't stand to gain or lose anything if we get divorced."

"Why not? She's very wealthy."

"She has money, yes. But so do I. I started saving the day I began moonlighting in emergency rooms, and I've made some lucky investments. But the real issue here is legal. We both signed a prenuptial agreement before we married. If we were to get divorced, each person would leave the marriage with exactly what he or she brought into it."

Agent Morse studied Chris in silence. "I didn't know that."

He smiled. "Sorry to punch a hole in your theory."

Morse seemed suddenly lost in thought, and Chris sensed that for her, in that moment, he was not even there. Her face was more angular than he'd thought at first; it had its own odd shadows.

"Tell me this," she said suddenly. "What happens if either of you dies?"

As Chris thought about this, he felt a hollowness high in his stomach. "Well…I believe our wills kick in at that point. And those override the prenup. At least I think they do."

"What does your will say? Who gets those lucky investments you made?"

Chris looked at the floor, his face growing hot. "My parents get a nice chunk."

"That's good. And the rest?"

He looked up at her. "Thora gets it all."

Morse's eyes flashed with triumph.

"But…," Chris protested.

"I'm listening."

"Thora is worth millions of dollars. What would be the point? Kill me to get an extra two million?"

Morse rubbed her chin for a few moments, then looked up at the narrow window set in the top of the wall. "People have been killed for less, Dr. Shepard. A lot less."