The officers either side of Porter moved forwards in tandem, Everett squeezing off three more shots at the boat as it arced out into the river. Kaye kept his gun trained on the water where Bolton had landed with an explosive splash seconds before, the surface churned into a thick froth, the colour of the head on a pint of Guinness. Porter looked up towards the boat, a hundred feet away now and accelerating out of range. Still no sign of Locke. He saw Stenner glance over his shoulder, but his face was too far away to read the expression.

Porter looked back to the water by the jetty as Bolton broke the surface, floating face down, arms spread wide. He checked that Kaye had him covered before turning his back on the river to take the rungs two at a time on the way down, Everett following close behind. Bolton bumped gently against one of the wooden jetty legs as Porter reached the edge. He leant forwards, tapping Bolton’s back twice and snapping his hand back, taking nothing for granted. No reaction. He reached under the nearest armpit and pulled upwards to flip him over.

‘Christ, he’s heavy.’ Porter grunted with the effort. ‘Give me a hand,’ he said over his shoulder to Everett. The two of them grabbed a handful of fabric, flipping Bolton over, and he dipped back below the surface for a second as he was turned onto his back. ‘Armpit each,’ Porter said briskly, and they spun him round so his feet pointed out into the river, snaking their arms under and around, clasping on to his shoulders.

‘On three?’ asked Everett, and Porter nodded. ‘One, two—’ The three was replaced by a groan as they both pulled up and backwards, inching Bolton onto the rough wooden boards. They angled him round to lie him lengthways, and Porter knelt beside him. He saw Bolton’s eyes move behind closed lids.