And then the out-of-control helicopter hit Karswell Hall. The rotors scythed into the apex of the roofline and shattered into wreckage like bursting shrapnel. The chopper flipped and smashed through the top of the house as though it were made of balsa wood, and was swallowed in a giant fireball that lit the sky and made Ben, Wolf and Jeff shield their eyes from its blinding flash. In seconds, an inferno engulfed the interior as hundreds of litres of aircraft fuel burst from its shattered tanks, ignited to thousands of degrees and poured like liquid napalm through to the lower floors. Fire erupted from the ground-floor windows with volcanic fury.

All Wolf and Jeff could do was gape and shake their heads in disbelief. Ben began running a few steps towards the house, but then stopped and turned away from the sudden scorching heatwave as a second and far bigger explosion ripped through the building and shook the ground under his feet. The helicopter crash had ruptured a gas main.

And now the three of them watched the rapid and total destruction of Karswell Hall. In seconds, most of the roof had fallen inwards and become a giant crater from which fire and smoke leapt high into the night sky. Sections of blackened stonework began to crumble and lean and fall. The inferno was pouring from the bay windows of what had been the banquet room. Nobody inside could have escaped being roasted alive.

The Pandemonium Club had wanted to create Hell on Earth. Now they’d found it.

‘They’re toast,’ Wolf said.

‘Crispy bacon,’ Jeff said.

Ben was about to say something when a movement near the house caught his eye. A small, dark shape moving slowly in the midst of the smoke and patches of fire that had broken out all across the lawn. He thought it was an animal, but it couldn’t be.

Ben brought the rifle back to his shoulder and peered through the scope. What he could see moving about over there was the broken, crawling, torn and crippled shape of a man. Blood covered his face and his glasses were gone. He was clawing himself away like a half-crushed spider from the burning house, dragging one leg behind him.

Saunders must have been thrown clear of the helicopter when it hit the house and flipped over. He must have come tumbling down the slope of the roof as the shattering rotors diced the air all around him, then fallen three storeys to the ground below. And he was still alive.

Ben could have just shot him then, clean and surgical. Instead he lowered the rifle, tossed it to Jeff and drew out his pistol.

‘Stay back. He’s mine.’

Ben walked towards the blazing house. The billows of black smoke stung his eyes and the heat of the raging conflagration was tremendous. He kept walking. His grip on the pistol was relaxed. He felt calm.