The whole exchange has been unsatisfactory, and recalls Nat’s bitterest complaints. It spikes any lingering notion of Dyer’s that the dark star of his nostalgia might have fertilised, about giving to the newspaper they both had worked for the first crack at Marvar’s story.

Still, the young man’s reaction confirms what Dyer in his old reporter’s bones believes. If Marvar spoke the truth about his wife, then he was likely to be telling the truth about fusion. And if that were so, then the right recipient for Marvar’s post-it note is not Lionel Updark.

‘Wait, what’s your number? If I hear anything …’

Chapter Twenty-four

DYER RETURNED THE HANDSET TO its charger on the bookcase, beside Astrud’s photograph, and then went over to where he had hung his shoulder bag, checking inside. The bag had not been in his line of vision. Although it was absurd to suppose that anyone had crept in and riffled through it while he was talking on the sofa, he felt the irrational need to make doubly sure.

He zipped it up and stood at the window, staring out. His conversations had depressed him, he was no further along. His mind kept returning to Marvar and his post-it note.

What do you do when something like this tumbles out of the sky into your life? Dyer yearned to hand it in, get rid of it. But if not to Updark, then who? He’d looked for signs and there were none. He had hoped the cracks in the pavement would tell him. If he had believed in a higher power, he would have implored it to point a way.

The post-it note was not his only concern. He couldn’t stop thinking about the life-or-death implications of what he chose to do, for Samir, Rustum, Shula and Jamileh. He had already promised to withhold information. Yet further holding him back from reporting Marvar’s findings to Updark or Euratom, or another neutral body, was Dyer’s fear that the Revolutionary Guard would simply execute Shula, as they’d have no further need of her as a bargaining chip. Then again, if Marvar and Samir had been picked up, this would render Shula’s life worthless to the unscrupulous entities who may have captured her.

Meanwhile, where to put this pestilential scrap of paper? Marvar’s information was so radioactive that it ought to be kept locked in a vault with Madame Curie’s cookbooks. It wasn’t safe to carry about.

Dyer stands there with his thoughts.

On the far towpath, a shaven-headed man cast off a long barge. A woman walked by, pushing a pram that bounced up and down. Shula and her baby daughter. Too hard to think of them.