The head of the President’s personal security detail responded with a thumbs-up from the front passenger seat of the SUV called the ‘Halfback’, a Chevrolet Suburban jam-packed with would-be first responders and their FN P90 submachine guns. Wallace worked his way down the line, giving vehicles that included decoy limousines, sweepers and an intelligence truck a final check before reaching the end, where he climbed into a truck-sized van and approached a wall of LCD computer screens.

He gave them a once-over before picking up a radio. ‘Roadrunner to Overwatch,’ he said. ‘Are you in position?’ He heard the rotor blades before he heard the reply.

‘Overwatch in position,’ said the helicopter pilot.

Wallace responded then picked up the radio that was connected to every vehicle in the convoy. ‘Operation Stagecoach is a go,’ he said. ‘Roll out. ETA to delivery: twenty-eight minutes.’

THE GREEN circle had halved in size again, the ball now bouncing over a single prison block.

‘Samurai to Ronin One,’ Clarke barked. ‘Move through Echo Gate and proceed to Block Bravo. I repeat, move to Block Bravo and wait for further orders.’

‘Ronin One to Samurai,’ the soldier said, ‘Copy. We are on the move.’

Organised as a single brick of four for this operation, the Ronin burst through the door beside the East Gate of Goulburn prison. Dressed in full operational night gear – head to toe in black with body armour, balaclavas and tactical gloves – they charged across the birdcage and took cover behind a wall, two of them standing on each side of a steel gate.

Ronin One issued a series of orders via hand signals and the gate began to open, a technician remotely flicking the switch.

One. Two. Three!

Ronin One swung his Colt M4A1 assault rifle around the corner and provided cover for Ronins Three and Four as they sprinted across the freshly opened space to take the far flank. Watching through his holographic gun-sight, Ronin One waited until they were in position before ordering Ronin Two to the near flank. With the corridor taken and secure, they jammed their rifle butts into their shoulders and stormed along the passageway. They stopped when they reached a double set of steel doors.

‘Ronin One to Samurai. We have reached checkpoint Delta Block.’

Clarke swore as he stared in astonishment at the screen. The green ball had finally became a dot. But it was now on the other side of Delta Block.

‘Copy,’ the soldier said when he was given the coordinates.

‘GREETINGS, my child,’ said the Mahdi, phone pressed firmly to his ear. ‘Is all in place?’

He listened to the reply.

‘Good,’ he said. ‘I am proud of you, my son. Proud of both of you. Hold on a second.’

The Mahdi thought he’d heard a noise. Something outside his door. He placed the phone under his leg to hide the glow and listened hard.