But the GMC wasn’t changing lane.

It kept on going down the highway.

Alex frowned as it sped on ahead. The airport signs flashed by and were left behind. Strange. Hadn’t Murdoch said they were taking Zoë straight to the airport? Then where were they taking her?

She drove on. Time passed. The CCR album came to its last track and ended. She barely noticed. The sky had clouded over now, and rain began to spatter on her windscreen.

Now the GMC was heading off the highway and into open country. Woodland flashed by, and the traffic started thinning out. They were travelling further and further away from Langley and Washington DC, heading God knew where. Something told Alex to hang back, and she touched the brakes to widen the distance between her and Callaghan.

Deeper and deeper into country. Rain hammered against the glass, the wipers beating time. The road became snaky and narrow, and she hung right back so that she could just about keep the GMC in sight but without being spotted.

Now she was seriously perplexed. What was going on here? She wished she could call Murdoch at Langley. Stupid, stupid, to have left her phone behind.

The Beetle’s dashboard clock was approaching 11 a.m. and the fuel gauge needle was beginning to dip worryingly into the red when the GMC finally pulled off the road. Trailing sixty yards behind, Alex saw the brake lights come on as it lurched onto an overgrown forest track, splashing through puddles. She followed cautiously.

The GMC bumped and bounced down the track until it came to a pair of tall iron gates half-hidden behind ferns. The rain was lashing down now.

Alex killed the Beetle’s engine and coasted the final few yards, gently halting the car behind the cover of some bushes. She climbed out into the downpour and hid in the side of the lane, watching as one of the agents got out, walked up to the gates and undid a padlock. Chains rattled loose. The agent creaked the gate open and the car drove through.

Seconds later she heard screams.

Zoë’s voice.

No phone, no weapon. Alex had never felt so naked. She crept through the bushes a few feet, careful not to snap any twigs. Her hair and clothes were quickly soaked from the rain, sticking to her skin. She peered through the foliage. Beyond the gate was a large, sprawling house. It looked like some kind of hunting lodge, expensive, secluded. The gardens were overgrown, as though the place were used only occasionally.

Callaghan’s men were dragging Zoë out of the GMC and towards the house. Callaghan led the way. He opened the door, and the men hauled Zoë inside, kicking and screaming. Then the door closed.

Alex’s heart was thudding hard and fast. She checked her watch. It was 11.09 a.m. She tried to figure out where they were.

Alex crept through the open gate and moved quickly across the overgrown garden, moving carefully through the trees and shrubs to avoid being seen from the house’s many leaded windows.

She crept right up to the house. Her heart was in her throat. She listened. There was nothing.

And then there was the click of a pistol hammer being cocked, and the hard metal of it to the back of her head.

‘Careless,’ said a man’s voice she’d never heard before. ‘You were following them. But I was following you.’

She risked a glance behind her. The man with the gun was slightly built, expensively dressed with a long black raincoat over his suit. His hair was gingery red. There was a twinkle of humour in his eyes. Rain pounded off the canopy of his umbrella.

‘You’re Slater,’ she said.

‘And you must be Agent Fiorante. I’ve heard all about you.’

The realisation was dizzying. Callaghan and Slater. The whole time, they’d been in it together.

He twitched the gun barrel. ‘Move. Keep your hands raised. Lower them and you’re dead.’

Alex walked. He prodded her inside the house. It was sombre inside. Dark wood panelling glistened dully in the darkness. A stone fireplace was filled with old ashes and blackened logs. The heads of animal trophies stared down from the walls, eyes glazed, spiky antlers and curled horns casting weird shadows. She shivered, dripping water across the flagstones.

Footsteps echoed up the hallway and a door crashed open. Callaghan strode in. His face was twisted in fury. Three more men filled the doorway behind him, pistols drawn.

‘Surprise visitor,’ Slater said.

Callaghan stared at her. ‘That was smart of you, Fiorante. But there’s a fine line between smart and dumb, and you just crossed it.’ He motioned to the other men. ‘Frisk her.’

They searched her roughly, but carefully. ‘She’s clean.’

Alex brushed wet hair from her face and glared defiantly at Callaghan. ‘What have you done with Zoë?’

Callaghan smiled. ‘You want to go meet her? Be my guest.’

Alex was dragged down a twisty, shady corridor by the agents as Callaghan and Slater led the way. There was a heavy iron-studded door in an alcove at the bottom of the passage, down some steps. Callaghan took a long iron key out of his pocket and unlocked it. He jerked the door open and the agents shoved Alex inside. She tumbled down a flight of stone steps and landed hard on a concrete cellar floor. She tasted blood on her lips as she staggered to her feet.

Slater casually descended the steps towards her, that twinkle in his eye. He stopped halfway down and leaned on the iron stair rail. ‘What a shame,’ he said, eyeing her up and down. ‘She’s so nice.’

Alex heard sobbing behind her. She turned. Zoë was slumped against the wall in the shadows. Her face was wet with tears and there was a cut over her eye. Alex went over to her and held her. ‘You bastards,’ she hissed at them.

Callaghan walked down the steps and stood next to Slater. ‘I guess this is where we part ways, ladies.’ He reached into his coat and drew out a Glock 9mm. He pointed it at Zoë, then swivelled it to aim at Alex. Alex refused to flinch. No way would she show him fear.

Zoë whimpered, clutching her hand.

‘Fuck you,’ Alex said.

‘I really like this woman,’ Slater said. ‘She’s feisty. Shame I can’t get to know her better.’

‘She’s a pest. And pests get eradicated.’ Callaghan squinted down the sights, getting ready to fire.

‘Wait,’ Slater said.

Callaghan lowered the gun impatiently. ‘What?’

‘Don’t shoot them.’

‘What?’

‘Don’t shoot them. I have a better idea.’ Slater grinned. ‘How often do you come out here?’

‘Not as often as I’d like,’ Callaghan said. ‘You know how it is.’

‘Say, once every four, five months?’

‘In a quiet year.’

‘This a quiet year?’

‘This is a crazy year.’

‘Well, how about we just shut these two up down here and come back in six months or so to see how they’re getting on?’

Callaghan made a face. ‘There’s going to be a hell of a stink down here.’

Slater shook his head. ‘I never told you about my dog, did I? I had this retriever, when I was a kid. It was OK for a while, but then I got tired of the damn thing, so I shut it up in a basement to see what would happen. Took a pretty long time to die, actually. But I can tell you that the stink dies off after a while, once the rats have eaten most of the meat away. Maggots take their share, then the body fluids all dry up. You’re left with kind of a dried-out husk.’

‘You’re a sick bastard,’ Alex said.

‘I like it,’ Callaghan said. ‘What do you think, ladies? Give you some time to get to know one another better. You might even try digging your way out. Only the foundations go down awfully deep and we’re built on solid bedrock here.’

‘It’ll give you something to do while you’re dying,’ Slater said with a grin. He checked his watch. ‘We’d better move. The senator’s plane is waiting for me.’

Alex scowled at him. ‘Senator?’

Slater’s grin widened. ‘Who did you think was bankrolling this thing, the Salvation Army?’