The wind whistled, chill and sharp, its gusts pulling at Connor like claws. He swung precariously over the abyss, clinging on for dear life as shards of glass spun and sparkled into the city’s night. The glazing, weakened by the bullet, had given way under his weight. On pure instinct alone his hands had reached out and caught the lip of the frame, preventing him from plunging to certain death. Now he hung, small and fragile as a fruit bat, from the underbelly of the Sky Walk.

‘CHARLEY!’ he screamed at the top of his lungs.

Mid-fight she glanced his way, but didn’t see him at first. Then she looked down and stared in horror at his terrifying predicament. Seizing upon her distraction, the guard swung his baton at her head. At the last second Charley ducked, but she still caught a glancing blow. Then, with the fury of an avenging angel, she laid into the guard, her tonfa-style armrests becoming a blur of steel.

But all the while Connor felt his grip slipping …

He looked to Amir, but his friend was in serious trouble himself. The other guard had him pinned against the wall, throttling him with his baton. Amir gasped and spluttered, his eyeballs bulging and his fingers clawing at the man’s face.

Mr Grey, kneeling close by, watched the chaotic scene with blithe amusement. ‘I would help you, Connor, but I’m a little incapacitated at the moment.’

Connor thought the only help the assassin would give him would be to help him on his way. So, muscles straining and pulse pounding, Connor tried to pull himself back into the Sky Walk. The glass gave him little purchase and the sweat on his fingertips only added an unwanted slickness to his grip. He cried out in horror as he lost hold with one hand and dangled by a single arm in the darkness. Like a leaf waiting for a final gust to blow it off the branch, Connor clung on.

The ache in his muscles grew unbearable and his grip weakened with every passing second. He knew in his heart that he was going to fall, that he would plummet to certain death – either on to the observation deck below or all one hundred floors straight down to the concrete paving of the street …

Then he heard a dull thunk and a guard’s bruised face appeared in a nearby pane, his features squished against the glass. A second later Charley skidded to a halt by the hole, locked out her brakes and reached down with the end of her armrest.

‘Grab hold!’ she cried.

Connor seized the metal tube with his free hand and began to pull himself up. Charley, teeth gritted and muscles straining like the cords of a rope, took all of Connor’s bodyweight. Slowly but surely, Connor worked his way back into the Sky Walk. But, as soon as he laid an arm on the floor, Charley kicked him in the face!

Connor reeled and almost dropped back through the floor. Charley then stamped on his hand. Connor gasped in pain and shock.

‘NO!’ she cried, her eyes wide with panic as Connor struggled to keep a grip. ‘It’s not me!’

Glancing sideways, Connor spotted Mr Grey with the neuro-controller in his hand. A cruel smile cut across his lips. ‘Oh dear, Connor, your saviour has just become your executioner!’

The assassin pressed the controller’s display panel and Charley’s leg began to rise.

‘You will not control me!’ yelled Charley fiercely. Her face contorted into a knot of furious concentration as her foot went to stamp on Connor’s hand again.

Connor clung desperately to the edge, powerless to stop her. He saw Charley trembling in her chair as she battled against the impulse to kick him to his death.

‘You will NOT control me!’ she screamed, and, with a super-human effort of willpower, she forced her leg back on to her chair.

Mr Grey stabbed at the controller, but Charley’s limbs refused to obey its command. Somehow Charley had overridden the neuro-controller’s signals.

‘Well, if I can’t control you, I’ll just have to torture you,’ he snarled, pressing another button on the screen.

All at once Charley began to convulse. Her knuckles went white as she fought against the crippling pain to keep a grip on the handle of the armrest.

‘I … can’t … hold … any … longer …’ she gasped with a look of despair at Connor.

‘It’s all right,’ said Connor as her body jerked violently and she was forced to let go.

No longer supported, Connor plummeted back through the hole. Grabbing for anything he could, his fingers clasped around a carbon-fibre spoke of Charley’s wheelchair. With the last of his strength he began to pull himself up again. But his weight was dragging the wheelchair towards the edge, its rubber tyres squeaking across the glass floor.

‘Now that’s a real catch-22,’ said Mr Grey with a cruel laugh. ‘Save yourself … or Charley?’

The chair slid another fraction of a centimetre closer to the edge.

‘I wouldn’t judge you for saving your own skin, Con–’ Suddenly Mr Grey went into spasm. The assassin let go of the neuro-controller and collapsed to the floor. Behind him stood Amir, bruised and bloody, iStun in hand.

‘AMIR!’ shouted Connor as the wheelchair shifted to the very lip of the hole.

His friend dived for him, grabbing his wrist and pulling him to safety. Then he dragged Charley’s wheelchair away from the edge. Connor lay panting at Charley’s feet, unable to quite believe his near-death experience was finally over. ‘Are you OK, Charley?’

Charley nodded. Her face grey and washed-out, she looked utterly drained, as if the plug had been pulled on her. ‘Sorry … for kicking you,’ she murmured.

Dragging himself to his feet, he kissed her on the cheek. ‘Forget about it. It wasn’t you. I’m just amazed you managed to override the commands.’

‘It was like having a fight with myself,’ Charley explained weakly. ‘Two voices battling in my head.’

‘Well, let’s get rid of that other voice,’ said Amir. Picking up the neuro-controller from the floor, he prised open the back and, after cursory examination, tore out the electronics. ‘That’s the end of that,’ he declared, tossing the remnants down the hole.

The three of them watched the pieces twirl away into the night.

‘So what did you do to him?’ asked Connor, nodding at the final guard flopped against a window, his mouth open and drooling.

Amir raised an enigmatic eyebrow. ‘While you were hanging around, Connor, we were dealing with the bad guys!’

They both laughed, but Connor’s laughter was cut short when he saw Mr Grey looming over his friend. ‘Behind you!’ he cried.

Spinning round, Amir drew his iStun and jabbed the metal prongs into the assassin’s side again. But Mr Grey didn’t even flinch.

‘Run out of charge?’ asked the assassin, glancing at the red light blinking on its display. With brutal efficiency, he knife-handed Amir in the neck, striking his carotid artery and instantly blacking him out. Amir slumped to the ground.

With Amir out cold and Charley weakened to the point of infirmity, only Connor and Mr Grey were left standing.

‘Whatever you did to me, Connor, it appears your friend’s stun-phone has recharged me!’ The assassin bent down and reclaimed his gun. But, rather than taking aim, he holstered the weapon, strolled over to a comatose guard and picked up a baton instead. ‘I’ve decided I’m not going to shoot you after all, Connor … I’m going to beat you to death.’

The assassin advanced on him, tapping the stick in his open palm.

‘So much for a simple execution!’ said Connor, looking for something to defend himself with. He spotted Charley’s other armrest lying on the floor. He darted for it –

But Mr Grey lashed out. Connor dived to one side and made a desperate grab for the armrest. Almost at once the baton came back, smashing down on to the floor and catching his outstretched hand. A rocket of pain shooting up his arm, Connor was forced to roll away. He’d barely got to his feet when Mr Grey brought the weapon round towards his head. Connor ducked and the baton struck the window behind him with such force that it smashed the pane, glass showering down.

‘You can’t dodge me forever!’ said Mr Grey.

The assassin drove Connor back with a series of brutal swipes until he was trapped against the windows on the opposite side of the Sky Walk. Connor realized the assassin was right and braced himself for the inevitable blow. Mr Grey feigned an attack to the left before swinging in hard to the midriff.

Connor took the impact full force – a bone-sickening crack reverberating through the Sky Walk. But it wasn’t Connor’s ribs that had snapped. It was the baton! Mr Grey stared at the broken stick in his hand, then at Connor, who still stood before him, unbowed and unbeaten.

A flicker of incomprehension passed across his ice-grey eyes.

Connor simply smiled. Just as Lăolao had taught him, he’d locked in his qi, fusing his life force with his body and turning himself into a human shield … Iron Shirt.

Before Mr Grey could overcome his astonishment, Connor concentrated all that qi into his fist and punched the assassin in the solar plexus with the devastating power of Iron Hand. A sharp crack of ribs now did echo through the Sky Walk. The assassin exhaled in open-mouthed shock, his eyes wide in both pain and disbelief that a mere boy had the skill and speed to defeat him in combat. Unable to recover his breath, he staggered, then stumbled over the body of a guard and fell …

‘Watch out!’ cried Connor, instinctively trying to save the man as he tumbled through the hole in the floor. But it was too late. The assassin dropped three storeys straight down to crash into the skylights of the lower observation deck where he sprawled lifeless on the cracked glass.