Ben scoured the controls. Sure enough there was a large, brown button in front of him. He shrugged, took a deep breath, and hit it.
To Ben's total surprise, the noisy engine coughed and spluttered into life. Outside, there was another deafening explosion.
'Drive it!' Annie screamed. 'Get us out of here!'
'I don't know how!'
'The pedals,' she yelled at him. 'One's an accelerator, one's a brake. Steer left and right using those red levers on either side.'
Ben located everything she was talking about. Sure enough, on each side of his seat there was a lever, not unlike the handbrake of a car. He gripped them firmly, peered through the viewing window, and gingerly pressed his foot down on the accelerator. The Chieftain shuddered into movement.
'Faster, Ben. We've got to get out of here.'
Ben pressed harder and the tank accelerated. Just then, however, there was an explosion in front of them. Rubble sprayed everywhere, blocking Ben's vision, and he instinctively pulled hard on the right-hand lever. The tank swerved sharply; Ben released the lever to straighten up, but saw himself driving directly towards a hut. He swerved again, missing the building by a whisker. His heart was in his throat as he straightened up once more. In the distance he could see the forest, so he gritted his teeth and pressed the accelerator down full throttle. The tank sped away from the training field and the sound of the bombs grew marginally fainter.
'That,' Annie shouted, 'was a close shave!'
'I think we're clear,' Ben started to say, but before he could finish, something caught his eye. A small box nestled in among the controls in front of him started flashing red. There were words, and he squinted his eyes to read them.
REMOTE CONTROL GUIDANCE SYSTEM. OPERATIONAL.
He blinked, then pulled on one of the levers; it did nothing. He let go of the accelerator; the tank maintained its speed.
'Annie,' he shouted, unable to hide the panic in his voice. 'I've lost control.'
'What?'
'I can't control it. Look!' He pointed at the flashing warning sign. 'Something else has taken control of the tank. I can't steer. I can't stop.'
'I don't believe it,' Annie yelled.
'We're a moving target! We're being controlled by the RAF for the training exercise! WE'RE A MOVING TARGET!'
And as she spoke, the tank performed a sharp turn. 'We're heading back!' Ben shouted. 'We're heading back to the bombs!'
The roar of the planes and the crash of the explosions grew louder; the ground seemed to tremble.
'Joseph!' Ben shouted. 'You're the scientist. What do we do? How do we get control of the tank again?'
Joseph hauled himself to the front of the tank, but all he could do was stare at the remote control unit. 'I don't know,' he said.
'What do you mean, you don't know?'
'I can't start dismantling it now, Ben.' And as if to confirm what he had just said, the tank was thrown sideways onto one set of wheels, making them tumble around inside. Ben shouted in pain as one of the steering levers dug sharply into his ribs.
'Ben!' Annie called. 'Are you all right?'
'Fine,' Ben growled through gritted teeth. His mind was suddenly clear. The planes were actively targeting them now, but there was no way he was going to give in without a fight. He leaned forward, his body shuddering dramatically from the movement of the tank, and grabbed the box with both hands. He took a deep breath and then, with all his might, tugged on it. The metal dug sharply into the skin of his hands and he hissed with the pain, but rather than let go he tugged again.
And again.
And again.
Finally, with a great heave, he managed to pull the box away from its fittings. A tangled mess of wires sprouted from the back. 'Pull them,' Joseph shouted. 'Just pull the wires as hard as you can.'
Ben did as the old man said. A shower of sparks briefly illuminated the inside of the tank, but for a minute nothing seemed to be happening. The three of them looked at each other with undisguised fear.
And then the tank started to slow down.
'Quick, Ben,' Annie urged. 'Turn us round again.'
Ben didn't need telling. He slammed his foot on the throttle and yanked the right-hand steering lever. The tank almost seemed to skid as it pulled round in a tight turning circle and sped away from the devastation of the training site. Bombs fell left and right. Left and right. The trio remained silent, praying that none of the planes overhead scored a direct hit, holding their breath, every moment fully expecting to be battered to bits.
Eventually, though, Ben became aware that the noise of the training exercise was behind them, but he didn't slow down. Not yet.
Only when they were well clear did he dare to take his foot off the throttle. The Chieftain ground quickly to a halt, and for a moment they all sat there, listening to the churning sound of the engine turning over, their faces white and their body trembling.
Even above the rumble of the engines, Ben could hear the others' breathing. Heavy. Laboured. But relieved.
'I think we're safe,' Annie gasped.
Ben nodded. 'For now,' he panted. He turned to look at his cousin, and she smiled at him, a bead of sweat trickling down her dirty face.
'Nice driving,' she said.
Chapter Eighteen
How long they sat there, trying to regain their breath and their composure, Ben couldn't have said. It was just a relief to be safe.
Joseph was the first to speak. 'We can't stay here,' he said. 'They will come for us soon. And besides, I need to do something about Vortex.'
Ben turned to look at the old man. The cut and bruises on his face were sore, and there were dark bags under his wild green eyes. He looked to be in a worse state than he had when they first found him, and that was saying something.
'I don't know,' Ben replied nervously. 'Why don't we just try and find someone in charge. Alert them to what's going on.'
Joseph smiled. 'And you think they'll believe you? I've been trying to tell people about strange things happening at Spadeadam for years. Trust me, it's not what they want to hear.'
'Yeah, but I'm not—' Ben cut himself short.
'Not mad?' Joseph asked delicately. 'No, I would have to agree with that. But listen to me: Lucian will be scared that other people know of his device. Believe me, Vortex will be leaving that bunker any time now, if it hasn't done already. And if you want to hand yourself over to the RAF, that's up to you. Just make sure you don't accidentally give yourself up to one of Lucian's stooges. It's difficult to tell the difference between friends and enemies in this place, I've noticed.'
'He's right, Ben,' Annie said. 'We can't risk it. And if we're the only people who know about Vortex, we're the ones who have to stop it.'
Ben closed his eyes briefly. His body ached from being thrown around the uncomfortable chassis of the tank; there were already blisters forming on his hands from where he had been tightly gripping the steering handles. But then he looked at Joseph. The old man was a state, his body beaten and bruised. He had taken more punishment than anyone should have been expected to take, let alone a man of his age. Yet Ben knew from a single glance that Joseph would not be deterred from returning to the bunker and doing whatever was necessary to stop his brother. He also knew that he was in no state to make it there on foot.
'We need to follow the edge of the forest,' he said quietly. 'That was the way we came.'
'Listen to me, you two,' Joseph said. 'You've done enough to help me already. I'm an old man. I can take risks that you two can't. You don't have to help me do this. If you leave now, maybe you can get out of Spadeadam without anyone being the wiser.'
The offer was clearly sincerely meant, but Ben shook his head. 'If Vortex is as bad as you say it is, it's everyone's responsibility.' He looked at Annie. 'Agreed?'