The descent was just as dangerous as the climb, as the front tyres pattered and skipped over loose rocks and boulders and the whole vehicle threatened to tip over forwards. Now the looming castle walls were to their left. Ben killed the lights and shifted the box into neutral so he could cut the engine and coast silently back down to level ground. No movement from the castle. The snow kept drifting down over its roofs and courtyard. The place could have been deserted. But in just moments from now, things were set to liven up considerably.

Ben let the buggy roll to a halt thirty metres from the gates, hidden in the lee of the wall. With that, the Polaris had done its work. They disembarked. Ben took the fertiliser sack full of bombs from the load bay. He had the radio remote detonator trigger in his pocket. Glancing at Boonzie he could see a thrill in his friend’s face that he hadn’t seen since the last time they’d gone into combat together. Wordlessly, noiselessly, they made their way through the deep snow gathered at the foot of the wall and sheltered just by the gates, hidden from view of the castle windows. Ben peered inside the courtyard and could see the three identical boxy black Audi four-wheel-drives parked in a row out front, snow layered thickly over their roofs and bonnets. The druggies’ Mazda was still where he’d left it earlier. The Audis hadn’t been there then. Which meant that Hacker’s reinforcements had turned up in the meantime. All ten of them, right on cue.

‘Cold night,’ Boonzie muttered.

Ben took the remote from his pocket. ‘What do you say we warm things up a little?’

‘Thought ye’d never ask.’

Twenty-one detonator caps, twenty-one channels. Ben dialled up Channel One, said a silent prayer that it would work, and hit the SEND button.

It worked.

Faster than Ben’s prayer could have reached the ears of whoever might be listening up there, the radio signal from the remote activated the blasting cap wired to one end of the detonator cord. The cord itself was just a fuse, a hollow tube filled with volatile powdered explosive. But it was a very, very quick fuse. At the press of the button all hundred metres of line went up so simultaneously from end to end that from below it appeared as a single linear explosion, touching off the twenty packages of RDX in a spectacular leaping curtain of flame that lit up the night and seemed to shake the ground.