Callum stayed by the river for another twenty minutes or so, listening to the water and the beeping of the first few bats. He no longer worried about his fantasies, or the photographs, or the string. If he did think about his old urges, it was merely to observe, with a vague, wry sort of relief, that he had been ‘cured’ by that evening at Tamsin’s when he discovered the coins on the windowsill. The pain of her betrayal was purgative in its intensity, obliterating everything else. All his energy went on survival now: on not, under any circumstances, thinking about Chris. There was certainly no space for excitement.

This trip was a welcome distraction. It was nice to see his students in a new context, to watch them clumsily becoming themselves. Sophie’s forays into intellectual sophistication were particularly endearing. It was a strange age they were entering. Callum remembered his own early adolescence much more clearly than later periods of his life. During those four years, from thirteen to seventeen, he had experienced his strongest, most unified sense of self. He thought of himself as he was then. The teenaged Callum would have disapproved of sticking by a woman you knew to be cheating on you – but the teenaged Callum didn’t know how complicated things could be. That when the thing finally happened, your monstrous capacity for jealousy might not, after all, consume you; that you might find a way to go on loving alongside the terrible fact of betrayal. The trick was simply to turn your thoughts away. As soon as Chris came into his mind, Callum replaced the thought with something else. It was tiring but it was possible; he could do it, he felt, indefinitely.

Like now, for instance. He could feel Chris’s presence encroaching on his consciousness, so he threw himself outwards, back to the river and the bats and the clouds with their bellies lit highlighter orange by the setting sun. He thought about the woman at the bike-rental place with her tongue stud and her asymmetric fringe; about something funny that Hugh Brodie said at supper; about Karl Huber’s preternatural ability for languages; about Sophie Witrand, standing beside him in the fading light, asking him if he was scared of death. He thought about dying violently, a broken bottle, a knife in his guts. He thought about anything, anything at all, anything apart from Chris’s mouth on Tamsin’s mouth and Chris’s hands on Tamsin’s body and Chris’s (big, hard, infallible) cock in Tamsin’s cunt and their mouths and their heads and their bodies and their hands and their breath and their mouths and their tongues.

* * *

Chris checked his watch. Over four hours since he had stepped off from the base with his patrol: they were running well behind schedule. The sun was too high, approaching the dangerous heat of midday.