They entered a damp, dingy space with bare concrete walls and strip lighting. Dried patches of blood scabbed the floor. A bucket in the far corner overflowed with faecal matter. On the left side of the room Bowman saw a bundle of bloodied cloths on a wooden bench, next to a set of DIY tools. There was a power drill, a bone saw, a blowtorch, an iron bar, several knives, a claw hammer and a selection of rusted nails. A GSh-18 semi-automatic pistol.

And a cattle prod.

In the middle of the room, a rebel had been stripped naked and chained by his wrists and ankles to a metal bedframe. A short, stocky man with a chinstrap beard. Bowman had seen his face before, two lifetimes ago. Back in London. The lobby of the Broxbury Hall Hotel. On the TV. The mountainside interview with the reporter. The man had been wearing a pair of aviator shades back then, but the face was unmistakably the same.

General Moses Kakuba.

The rebel leader’s torso was covered in bruises. One of his ears had been sliced off. Chunks of flesh were missing from his arms and legs. A filthy rag had been stuffed into his mouth, stifling his screams of terror.

Colonel Lubowa stood over the prisoner, the sleeves of his army shirt rolled up to the elbows. He was beating General Kakuba senseless with his fists, delivering vicious blows to his stomach, his face. A second man dressed in the uniform of the Presidential Guard leaned against the bench, cheering Lubowa on. The dull wet slap of bone against flesh echoed through the cell as the Colonel shovelled a punch into the prisoner’s ribs.

Bowman’s stomach went cold. ‘Jesus Christ,’ he said.

‘What the fuck is going on here?’ Webb snapped.

‘I wanted to show you the secret interrogation centre we run down here. This is where we deal with the president’s enemies,’ Gregory replied casually.

‘This isn’t an interview room,’ Bowman said. ‘This a fucking torture chamber.’

‘More or less the same thing over here.’

Gregory flapped a hand at the terrified figure bound to the bedframe. ‘We found the general hiding in the ditch with some of his men. Trying to play dead. It’s a good job I recognised him, otherwise he might have been taken away with the wounded.’

Bowman felt sick. ‘Why are we here?’

‘The president wishes us to dispense with the general . . . once we’ve had our fun with him, of course. We’ve already enjoyed ourselves, as you can see. I thought you guys might want to take over. Think of it as a treat, for all your hard work.’

The guard roared with laughter as Lubowa struck the man again.

‘Thank you, Colonel,’ said Gregory. ‘We’ll take it from here.’