He climbs onto the upper platform and the spectacle is enhanced. He looks down on the London Eye where, twenty years and thirty-three days ago, he lived a moment that, for him, will never die. Not only the leap of his imagination but the jump in his groin as he stood behind her, pressing, folding his arms around her belly, the violence of his imagination matching the violence of what he would like to do to her. Her pale olive skin, silky dark brown hair, smell of sweet sweat.

He waits.

11.55 am

Five minutes to go. They should almost be in sight, the two of them. He thinks of the woman on the ground, staring at her screens, her nerves jangling, checking over her shoulder to see if anyone notices. Years of preparation in the balance. But, as yet, there is nothing to suspect or to see. He takes up position at the north viewing platform and removes binoculars from a case. Below a barge floats along the river in slow motion; stick-like figures pass each other on Hungerford Bridge. Cars on the approaches to Tower Bridge are stationary and he sees the drawbridge rise. Beyond, an elegant, high double-masted, cream-painted yacht glides up river; he quickly calculates what point it will have reached in five minutes’ time. Even his powerful lenses cannot individually pick out each pigeon on the steps of St Paul’s, but he can see the cluster. They’ll find a way of getting away; they always do.

The date, decided three years back, is a matter he wrestled with. The precise anniversary had a flaw – not merely the extra vigilance on the day but holiday season in the Palace of Westminster. He decided to wait. Allow no chance for lucky escapes, nor accusation of pointless gestures. Each generation might only have one chance. Twenty years and thirty-three days have passed; we have not gone away.