Before Alex Two could steady himself, Jack’s best idea was a head-butt to the face – his helmet cracking into the clone’s forehead – and then throwing the weight of his whole body against the clone until it slammed against the wall.

To his right, the wounded Alex One batted his hand around the stairs in search of his dropped submachine gun.

‘Gracie! Bloody help me!’

Jack wrapped one arm around Alex Two’s neck, ignoring the punches to every part of him the clone could reach, and tried to seize his weapon with desperate fingers. The angry clone wrestled back with both hands, a struggle Jack would definitely lose. Jack checked for a clear run to his left, forced all of his strength into the arm wrapped around his enemy’s throat, and charged towards the window.

Alex Two’s forehead shattered the glass, and formed several jagged edges that scoured the face that followed. There were no screams from the clone’s missing vocal cords, but his mouth opened wide and the rest of his body twitched in pain. Before his adrenalin peaked, Jack used his newfound strength to hold the injured clone in place. Alex Two fought with all his power to bring his head back into the living room, but could not stop Jack from squeezing his fingers into his collar and carving his neck back and forth against the broken glass.

The wall beneath the window painted itself red, and the clone’s resistance grew weak. Jack turned just in time to see Alex One’s submachine gun pointed in his direction, before his last enemy was shot dead by a flurry of bullets from Gracie above.

‘Are you alright?’ she asked from the top of the stairs.

‘Yeah,’ said Jack as Alex One toppled down the staircase, ‘peachy, thanks.’

Jack double-checked each of the three bodies in turn to make sure they were dead, and found that against the odds, he and Gracie really had won.

‘And I thought sharing a house with one Alex was difficult,’ he muttered, as he tended to the cuts in his forehead. Head-butting a clone with glass wounds to its face had not been his brightest idea.

‘What do we do now?’ asked Gracie.

‘We call comms, describe everything we’ve seen, and tell the real Alex he’s no longer special and unique. After that, we get out of here. Hundreds of thousands of houses between Oakenfold and New London, and this is where they searched.’

‘Just our luck,’ said Gracie.

‘It’s never luck,’ came a voice at the front door.

Gracie’s announcement had been right. After two and a half hours of waiting, Ewan had finally found his way to Lemsford.

‘You’ve got a theory?’ Jack asked him.