“You’ve noticed people often say more than they realise in the stress of the moment? She did say something a bit odd. It sounded no more than the typical ‘I told you so!’ outburst you sometimes hear. But I followed it up.

“‘I told him! I said time and time again, “Ernest, you’re keeping bad company! You’ll rue the day you took up with those scoundrels!”’ she said.

“She regathered her wits about her, though, pulled herself together, shut her mouth and thought a bit before feeding me some cock-and-bull story about gambling debts he owed to a London mob. He’d come away to Cambridge thinking they were on his tail that weekend. She was lying. But I had no way of denying it at the time. Could just have been true. It only begins to look like a string of porkie-pies when taken in consideration with past—and future!—cases.”

“Let’s take stock, sir,” Redfyre said hurriedly, watching his boss select two more files from the black box with enthusiasm. “We’re looking at three unsolved cases so far: a Cambridge tramp, a London accountant and a South American tango teacher. A throttling, a skull-cracking and a stabbing. Who on earth would connect them? Apart from the oddity of the final meal, which I believe we can discount in view of the many hostelries in the city, there are two elements they have in common. One I don’t yet understand the reason for—the bodies were flaunted, not hidden or disguised. Second, there’s a military flavour to each. Working backwards, the tramp, Dunstan, we know to have been a soldier of some sort. The Londoner still maintained links with a group of old brothers-in-arms, according to his wife, and indeed, it was at a war memorial that the killer chose to place his victim. The tangoist—though not himself a warrior—we could argue was the victim of a military man. An officer who served in Afghanistan, I think you said?”

“Good man! You’ve been paying attention. Now take a gander at these two.”

He slapped the two further files he’d selected in front of Redfyre. The inspector noted that they were of relatively recent date—opened and closed in the six months before he had joined the Cambridge force. MacFarlane went to the door to bellow for tea, leaving him to check the files for himself.