“No water,” he announced. “Or minimal.”

“Meaning Luke was dead when he went in the water?”

“I’ll send the tissues for diatomic analysis, but I don’t expect they’ll find much.”

The electric saw stopped, and seconds later Banks heard something rather like a combination grating and sucking sound, and he knew it was the top of the skull coming off. The assistant then cut the spinal cord and the tentorium and lifted the brain out. As he carried it to the jar of formalin, in which it would hang suspended for a couple of weeks, making it firmer and easier to handle, Dr. Glendenning had a quick look.

“Aha,” he said. “I thought so. Look, Banks, do you see that damage there, to the frontal lobes?”

Banks saw it. And he knew what it meant. “Contre coup?”

“Exactly. Which might explain the unusual angle.”

If a blow is delivered while the victim’s head is stationary, then the damage is limited to the point of impact—bones splintered into the brain—but if the victim’s head is in motion, then the result is a contre coup injury: additional damage opposite the point of impact. Contre coup injuries are almost always the result of a fall.

“Luke fell?”

“Or he was pushed,” said Glendenning. “But as far as I can tell, there are no other injuries, no broken bones. And as I said, if there was bruising, if someone hit him, say, knocked him over, then, unless there are any small bones in the cheek broken, we won’t be able to tell. We’ll be checking, of course.”

“Can you give me any idea about time of death? It’s important.”

“Aye, well…I’ve looked over Dr. Burns’s measurements at the scene. Very meticulous. He’ll go far. Rigor’s been and gone, which indicates over two days at the temperatures noted.”

“What about the wrinkling and whitening?”

“Cutis anserina? Three to five hours. Water preserves, delays putrefaction, so it makes our job a little harder. There’s no lividity, and I’m afraid it’ll be almost impossible to tell whether there was any other bruising. The water takes care of that.” He paused and frowned. “But there’s the discoloration around the neck.”

“What about it?”

“That indicates the beginnings of putrefaction. In bodies found in water, it always starts at the root of the neck.”

“After how long?”

“That’s just it,” Dr. Glendenning said, looking at Banks. “You understand I can’t be more specific, I can’t give you less than a twelve-hour margin of error, but not until at least three or four days, not at the temperatures Dr. Burns recorded.”

Banks made a mental calculation. “Bloody hell,” he said. “Even at the outside, that means Luke had to have been killed just after he went missing.”

“Sometime that very night, by my calculations. Taking everything into account, between about eight P.M. and eight A.M.”

And Dr. Glendenning’s calculations, perhaps because of his insufferable habit of being unwilling to commit himself to a specific time, were usually not far from the truth. In which case, Banks thought, Luke had died before Annie had even paid her first visit to Swainsdale Hall, let alone before she had followed Martin Armitage to the site of the drop.