There must be some mistake. Some terrible, terrible mistake. The chances were, of course, that he had made it, and as he stared, trembling, at the paper he realised, quite suddenly, that he had.

He had been looking for a negative number and had therefore assumed that that was what he was looking at. In fact his account stood at £22,347.43. In credit.

Credit . . .

He’d never known such a thing. Didn’t even know what it looked like. Hadn’t recognised it. Slowly, carefully, almost as if the figures might fall off the page and get lost on the floor, he sifted through the sheets one by one to try to find out where on earth all this money had come from. “Kenny,” “Kentigern,” and “Kermit” slipped by unheard.

It was immediately clear that it was regular amounts that had been coming in, once a week. There had been seven of them—so far. The most recent one had come in the Friday before last, which was as far as these statements went. The odd thing was that though the amounts were regular, they were untidy amounts, similar each week, but not exactly the same. The previous Friday’s payment was £3,267.34. The previous Thursday’s (they had each come in at the end of the week, three of them on a Thursday, four on a Friday) was for £3,232.57. The week before it had been £3,319.14. And so on.

Dirk stood up and took a deep breath. What the hell was going on? He felt that his whole world was spinning very slowly in what was, as far as he could judge, an anticlockwise direction. That prompted a vague recollection that the last time he had drunk any tequila, it had made his world spin slowly in a clockwise direction. That was obviously what he needed if he was going to be able to think about this clearly. He rummaged hurriedly through a cupboard full of dusty nine-tenths empty bottles of half-forgotten rums and whiskies and found some. A half-full bottle of mezcal. He poured himself a finger in the bottom of a teacup and hurriedly returned to his statements, suddenly panicking in case the figures vanished while he wasn’t looking.

They were still there. Irregularly large sums regularly paid in. His head began to swim again. What were they? Interest payments that had been accidentally credited to the wrong account? If they were interest payments, that would account for the fluctuations in the amounts. But it still didn’t make sense for the simple reason that over £3,000 interest a week represented the interest on two or three million pounds and was not the sort of thing that the owner of such an amount of money was going to allow to be misplaced, let alone for seven weeks in a row. He took a pull on the mezcal. It marched around his mouth waving its fists, waited a moment or two, and then started to beat up his brain.