Sam threw her arms up in an effort to shield herself from careening headfirst into the rough brick wall, but her forehead struck hard all the same. The impact drove her to her knees, but she quickly recovered enough to scramble unsteadily to her feet.

She spun round to find the two men engaged in a deadly struggle, both Milner's hands locked round Ferris' thick wrist, trying to wrestle the knife away. "Get out of here, Sam!" Milner grunted through gritted teeth. Conditioned to obey, she ducked round the struggling pair and staggered out into the corridor, trying to ignore her throbbing skull, intent only on seeking help.

As he and Ferris grappled over the weapon, Milner realised that the odds in this fight were stacked against him. Though the two men were roughly matched in height and reach, his opponent outweighed him by several stone. His own litheness and quick reflexes were of little help when set against the convict's superior muscle, honed during his years at hard labour. Then, of course, there were the disadvantages posed by his prosthetic leg, which cost him both in balance and in kicking power. But his worst handicap by far was the injury he'd sustained from Ferris' first wild lunge.

The knife had been aimed directly at his heart. Though Milner had instinctively dodged the thrust, he hadn't moved quite fast enough. The blade had slashed deep into his upper arm, quite close to the spot where a bullet had grazed him a few years before. He tried to block out the pain, but the warm gush soaking his sleeve warned him that the loss of blood would quickly sap his strength.

He redoubled his efforts to force the weapon from Ferris' grip, desperately trying to deflect the point from own body. The convict battled back, relentlessly using every advantage of strength and weight in his attempt to drive the knife home, pounding his free fist repeatedly into Milner's stomach. The detective grunted under the barrage of blows and tried to snap a knee into the other man's groin, knowing he was fighting for his life.

Sam, meanwhile, had flown up the corridor toward the cellblock where she knew she would find several officers on duty. She wrenched frantically at the door handle but found it securely bolted. With a scream she flung herself against the cold steel, beating frantically and shouting for help.

In seconds there was an answering yell followed by pounding footsteps. Satisfied that help was on its way, she turned round and shot back down the passage. Milner, she knew, was unarmed, and she didn't know how long he'd be able to hold this madman at bay. She peered cautiously round the door jamb, heart pounding like a kettledrum, praying that she wouldn't find her friend sprawled on the floor with the hilt of the knife sticking out.

What she saw wasn't that bad, but it was bad enough. Though still on his feet and fighting, Milner was clearly faring the worse in their desperate struggle. Ferris shoved him this way and that, trying to shake loose the detective's grip on his arm so he could finish him off with the knife. More frightening still was his shirt, heavily soaked with blood. It was obvious to Sam that he couldn't last much longer.

She wanted more than anything to come to his aid, but how? Ferris would swat her away like a fly. A weapon, that was what she needed! Something large and heavy, like a lamp or a chair, that she could wield with at least enough force to divert his attention until help arrived. Frantically she looked this way and that, but there seemed to be nothing, nothing useful in this long-abandoned place. Virtually the only portable items in view were a trio of red fire buckets hanging on hooks a short distance away.

It was ridiculous, she knew, but what else could she do? She snatched one up and ducked back into the fray. Ferris' back was to her, fortunately, so she swung the pail as hard as she could at the back of his head, knowing as she did so that the gesture was useless. The bucket was made of aluminium, for heaven's sake. She might as well bash him over the head with a rolled-up newspaper.

Sure enough, though the pail echoed with a hollow clang against his skull, the blow didn't so much as make him flinch. Sam groaned in despair. Then, in an idea born of sheer desperation, she jammed the pail down over his head, using both hands to hold it in place.

Mad though it seemed, the trick worked! Blinded and disoriented, the assailant's grip on the knife slackened. Milner seized his chance to wrench it loose. The weapon clattered to the floor and with a swift kick he sent it skittering into a darkened corner, safely out of sight.

Ferris let out a roar like an angry bull and tossed his head this way and that, trying to free it from the stifling darkness. Encountering resistance from Sam's determined grip, he jerked an arm back in a powerful blow designed to throw off his unseen attacker. It was more than enough to fling her off; she reeled back and crashed to the floor.

One glimpse of her motionless form was enough to energise Milner with a fresh surge of fury. He flung himself at Ferris as he freed his head, battering his face and body with the hardest punches he could muster. Then, before the other man could recover from the flurry of blows, his right leg flashed out and swept his legs out from under him. It was a manoeuvre he'd learned in police training more than a decade ago and, he noted with grim satisfaction, it worked just as well now as it had done then. He seized the convict's arm and twisted it up behind him, planting a knee in the small of his back and leaning with all his weight to hold him down.

His own reserves were nearly exhausted, but there still seemed to be a great deal of fight left in Ferris. He twisted and thrashed, trying to wrench his arm free and buck the detective off his back. Milner became aware of the pains riddling his body, the legacy of every punch he'd taken, and the agonising burning in his left arm. It took the last of his remaining strength to hold the larger man down until help arrived.

Mercifully, it didn't take long. He heard a startled "oi!" and the room was suddenly full of black uniforms. "Bloody hell! S'all right, Sarge, we got him!" said a voice as hands tried to pull him off. He couldn't hold back a sharp cry when someone grabbed his left arm. He sank back on the cold tile floor, drained, the red haze of pain before his eyes obscuring the sight of Ferris being cuffed and dragged away.

The next thing he knew a gentle hand was touching his face. He blinked to bring the figure kneeling beside him into focus; it was Sam, her copper hair in wild disarray, her face streaked with tears. "Sam," he groaned. "Are you all right?"

"Hush," she interrupted, her voice quavering. "I'm tickety-boo. But you're not. Lie still." He felt her hands gently tearing his blood-soaked sleeve and easing the fabric away from the gash, then pressing something against it in an effort to staunch the flow. Despite her care he sucked in his breath sharply as the fresh stab of pain surged through him like liquid fire. "Sorry," she murmured, sounding choked. "Got to stop this bleeding ... "

He reached out with his good arm and fumbled for her fingers but couldn't find them. "Sam, for God's sake, why did you come back? I thought you were safe - "

She looked startled at the reproof in his voice. "I had to," she replied simply, as though this were the most obvious thing in the world. "He was going to – I mean, I couldn't just let him - " she broke off, her eyes filling with fresh tears.

Before he could reply, they were interrupted by the arrival of the medical officer, who brushed her aside and took charge of the situation with cool-headed professionalism. In less than three minutes he'd applied a proper bandage and a tourniquet and organised two constables to help Milner onto a makeshift stretcher. An ashen-faced Sam followed as they carried him carefully upstairs to meet the ambulance which was already on its way to speed him to hospital.