“They mightn’t risk using it again after you’d indicated its potentialities to us. I expect they realised you would come round, only they couldn’t wait to help you to your feet. I doubt if they meant to put you out for good. And even then, your dead body on the bank would have drawn unwelcome attention to the canal in the end.”

“Surprising, really, they didn’t tip both of us in together. Simple solution.”

“Not if they had nothing to hand to weigh you down,” said Nightingale more calmly than he felt. “That’s what’s puzzling about Ivan. They threw him in, having presumably knocked him out first, yet left him to rise in time. It looks as though they acted almost on the spur of the moment, and certainly they must have been double quick about it. Yet I can’t believe they met him by accident and just seized the chance to even up some score against him. And if they were looking for him, how did they know which way he’d be coming? If they’d been following him, they’d have seen you, and wouldn’t have taken the risk. And if he turns out not to be in the canal, we’ll have to assume they took him off in a car. They couldn’t get far otherwise with a wet inert body. Then why not bring the car alongside him in the first place? Much easier and safer to hook him in.”

“Thought it was suicide at first.” Beddoes sounded weary. “Can’t have been, I suppose, in the light of the rest. Tell you how to find out if he’s in it—analyse a cup of canal water. If it’s five per cent proof, start dragging. Christmas eggs!”

Nightingale stood up. “I’m going now,” he said. “What about your people?”

“They’ve told them—it’s all right. Know better than to fuss for nothing. I say, wait a min. I must tell you—daftest idea I had, when I was hit.” Beddoes paused, and looked at the foot of the bed. “I thought it was a war starting—someone delivering a ballistic missile.”

Nightingale regarded him in silence for a second or two. “Did you?” he murmured, finally. “Poor old Bed!”

He took his gloves off the locker, dislodging a small card that had been lying under them. He picked it up. It was obviously intended for the hospital files.

“Good Lord!” he exclaimed, reading the only thing yet written on it. “Is your name Jonathan?”

“I didn’t choose it.”

“You know mine?” asked Nightingale.

“Brett,” said Beddoes sourly, as if he wanted to know in what respect that was superior to his own.

“That’s the second one really.”