“You confiscated it after an arrest. Instead of forwarding it as evidence, you hung on to it for a while. It was only when it couldn’t be located pretrial that anyone thought to come asking…”

“Okay, so you’ve done your homework, son—can we skip to the important stuff?”

“But this is the important stuff, Mr. Paterson. The lot of you seemed to run CID like it was your own little fiefdom—your rules and nobody else’s. The red light in Interview Room B? If you had anyone gullible enough in there, you’d say it was a lie detector and switch it on. I wonder how many confessions you got that way…”

Paterson was still smiling benignly.

“The row of optics in DI Gilmour’s office, hidden behind a bookcase—you even put the bookcase on castors so you could get at the booze quicker.”

“You’d have to ask him about that.”

“But I’m asking you.” Fox glanced down at his notes again. “Or let’s try this one—the practice of signing statements rather than writing them? Something you were supposed to have witnessed, but you weren’t there at all. Or if you were there, Gilmour would have made sure everyone had the same story to tell—because he’d have written the version himself. All you lot had to do was go along with it.”

Paterson’s gaze shifted to Rebus. “John, tell the man…”

But Fox slapped his hand against the tabletop. “DS Rebus is here as an observer. I’m the one you need to convince.”

“Convince of what?” Paterson’s eyes were drilling into Fox’s. “Sounds to me like you’ve already made your mind up—typical fucking Complaints. You should be thanking us and giving us medals—we were good at what we did. We got bad men off the streets. End of.”

“You didn’t get Billy Saunders off the streets. Evidence against him went missing. Statements were riddled with inaccuracies. Witnesses changed their stories after talking to you…”

“We can all agree that mistakes were made—and Stefan Gilmour walked the plank because of them.”

Fox leaned back an inch or two. “What do you think Billy Saunders is going to say?”

“How do you mean?”

“Procurator Fiscal will be talking to him. Might be Saunders will want to cut a deal, looking for leniency.”

“So what?”

“So he’s kept his mouth shut for thirty years, but he might think it’s time to spill what really happened.”

“Confess, you mean?”

“Maybe not to the murder—but the cover-up after.”

“Balls-up rather than cover-up.”

“You reckon that’s how he’ll frame it?”

“I don’t care what he does.”

“When was the last time you set eyes on him?”

“Billy Saunders? Twenty, twenty-five years.”

“Despite living in the same city?” Fox paused, making show of studying his notes. “When DI Gilmour resigned, who took control of Mr. Saunders?”