“I’d try and get a later train,” said Robin, “but obviously, with it being Christmas—”

“No, you’re owed time off,” he said brusquely. “You shouldn’t be working just because those careless bastards got flu.”

Robin, who had a strong suspicion that Barclay and Morris weren’t the only people at the agency with flu, said,

“D’you want more tea?”

“What? No,” said Strike, feeling unreasonably resentful at her for, as he saw it, forcing him to go shopping. “And Postcard’s a washout, we’ve got literally noth—”

“I might —might—have something on Postcard.”

“What?” said Strike, surprised.

“Our weatherman got another postcard yesterday, sent to the television studio. It’s the fourth one bought in the National Portrait Gallery shop, and it’s got an odd message on it.”

She pulled the postcard from her bag and handed it over the desk to Strike. The picture on the front reproduced a self-portrait of Joshua Reynolds, his hand shading his eyes in the stereotypical pose of one staring at something indistinct. On the back was written:

I hope I’m wrong, but I think you sent someone to my work, holding some of my letters. Have you let someone else see them? I really hope you haven’t. Were you trying to scare me? You act like you’re so kind and down-to-earth, no airs and graces. I’d have thought you’d have the decency to come yourself if you’ve got something to say to me. If you don’t understand this, ignore.

Strike looked up at Robin.

“Does this mean…?”

Robin explained that she’d bought the same three postcards that Postcard had previously sent from the gallery shop, then roamed the gallery’s many rooms, holding the postcards so that they were visible to all the guides she passed, until an owlish woman in thick-lensed glasses had appeared to react at the sight of them, and disappeared through a door marked “Staff Only.”

“I didn’t tell you at the time,” Robin said, “because I thought I might’ve imagined it, and she also looked exactly like the kind of person I’d imagined Postcard to be, so I was worried I was doing a Talbot, chasing my own mad hunches.”

“But you’re not off your rocker, are you? That was a bloody good idea, going to the shop, and this,” he brandished the postcard of the Reynolds, “suggests you hit the bullseye first throw.”

“I didn’t manage to get a picture of her,” said Robin, trying not to show how much pleasure Strike’s praise had given her, “but she was in Room 8 and I can describe her. Big glasses, shorter than me, thick brown hair, bobbed, probably fortyish.”

Strike made a note of the description.

“Might nip along there myself before I head for Cornwall,” he said. “Right, let’s get on with Bamborough.”

But before either could say another word, the phone rang in the outer office. Glad to have something to complain about, Strike glanced at his watch, heaved himself to his feet and said,

“It’s nine o’clock, Pat should—”

But even as he said it, they both heard the glass door open, Pat’s unhurried tread and then, in her usual rasping baritone,

“Cormoran Strike Detective Agency.”

Robin tried not to smile as Strike dropped back into his chair. There was a knock on the door, and Pat stuck her head inside,

“Morning. Got a Gregory Talbot on hold for you.”

“Put him through,” said Strike. “Please,” he added, detecting a martial look in Pat’s eye, “and close the door.”

She did so. A moment later, the phone rang on the partners’ desk and Strike switched it to speakerphone.

“Hi, Gregory, Strike here.”

“Yes, hello,” said Gregory, who sounded anxious.

“What can I do for you?”

“Er, well, you know how we were clearing out the loft?”

“Yes,” said Strike.

“Well, yesterday I unpacked an old box,” said Gregory, sounding tense, “and I found something hidden under Dad’s commendations and his uniform—”

“Not hidden,” said a querulous female voice in the background.

“I didn’t know it was there,” said Gregory. “And now my mother—”

“Let me talk to him,” said the woman in the background.

“My mother would like to talk to you,” said Gregory, sounding exasperated.

A defiant, elderly female voice replaced Gregory’s.

“Is this Mr. Strike?”

“It is.”

“Gregory’s told you all about how the police treated Bill at the end?”

“Yes,” said Strike.

“He could have kept working once he got treatment for his thyroid, but they didn’t let him. He’d given them everything, the force was his life. Greg says he’s given you Bill’s notes?”

“That’s right,” said Strike.

“Well, after Bill died I found this can in a box in the shed and it had the Creed mark on it—you’ve read the notes, you know Bill used a special symbol for Creed?”

“Yes,” said Strike.

“I couldn’t take everything with me into sheltered accommodation, they give you virtually no storage space, so I put it into the boxes to go in Greg and Alice’s attic. I quite forgot it was there until Greg started looking through his dad’s things yesterday. The police have made it quite clear they weren’t interested in Bill’s theories, but Greg says you are, so you should have it.”

Gregory came back on the line. They heard movement that seemed to indicate that Gregory was moving away from his mother. A door closed.

“It’s a can containing a reel of old 16mm film,” he told Strike, his mouth close to the receiver. “Mum doesn’t know what’s on there. I haven’t got a camera to run it, but I’ve held a bit up to the light and… it looks like a dirty movie. I was worried about putting it out for the binmen—”

Given that the Talbots were fostering children, Strike understood his qualms.

“If we give it to you—I wonder—”

“You’d rather we didn’t say where we got it?” Strike said, eyes on Robin’s. “I can’t see why we’d need to.”

Robin noticed that he hadn’t promised, but Gregory seemed happy.

“I’ll drop it off, then,” he said. “I’m coming up West this afternoon. Taking the twins to see Father Christmas.”

When Gregory had rung off, Strike said,

“You notice the Talbots are still convinced, forty years on—”

The phone rang in the outer office again.

“—that Margot was killed by Creed? I think I know what the symbol on this can of film is going to be, because—”

Pat knocked on the door of the inner office.

“Fuck’s sake,” muttered Strike, whose throat was starting to burn. “What?”

“Charming,” said Pat, coldly. “There’s a Mister Shanker on the line for you. It diverted from your mobile. He says you wanted to—”

“Yeah, I do,” said Strike. “Transfer it back to my mobile—please,” he added, and turning to Robin, he said, “sorry, can you give me a moment?”