A/N: Here's another one, ladies and gents. First things first: thank you to sakura-blossom62, Azteka and the two lovely people who PM'd me to confirm about haemostatic powders. Thank you also to AkoyaMizuno for your very understanding review. It was hjohn302 who mentioned that it would be nice to see Greg flummoxed for a change; as he's a very experienced DI, he ought to be pretty hard to shock, but if anyone is skilled enough to do it, it's our very own Captain/Doctor/Field Surgeon Extraordinaire, John Watson.

I mention Sally's hair only because I love Vinette Robinson's. I think she does such a brilliant job of making Donovan both really unlikeable and very human.

It had been an interesting chase, thought Greg as he dashed through the loading bay, swerving around the freight containers and narrowly avoiding crossing paths with Donovan. She, Sherlock, John, Gregson and himself had all taken a different direction in which to search, fanning out from the RV point at the centre to track their murderer. The RV point itself had been John's idea, as had carrying walkie-talkies due to the sheer size of the dockside yard. He had stood, straight and proud alongside him and Gregson, calmly assigning NATO phonetic call-signs and setting up a system of alerts and code words. Using their initials, he had devised a tactical plan that involved grouping senior and experienced officers with newer, greener ones whose alertness might be heightened by their eager attitude. As the two DIs set out the groups, John had explained their codewords as the uniformed officers strapped themselves into bulky Kevlar.

"If you spot either Borthwick or Casper, use 'Target Acquired'. If you see them moving towards another team, use 'Incoming' and the call-sign of whoever's leading. If you're in trouble, use the usual-'Urgent Assistance Required'. Got it?"

The assembled throng had murmured and nodded its assent, calmly spreading out in compass-point directions, heads down, weapons and batons raised. As Greg rounded the corner, a message crackled through on the walkie-talkies.

"Romeo Charlie to Sierra Delta One, incoming, suspect is on the move."

Rory Calhoun, a promising young sergeant from Charing Cross nick, had obviously taken John's military efficiency to heart. Message relayed, he disappeared from the airwaves, leaving them in the silence of the night. Greg (on his own, as the only firearms-ready officer on duty), pricked up his ears as the sounds of an almighty scuffle to his right. The scratching and metallic thuds died down, and he was just about to continue, torch and gun poised in front of him, when a soft whimper attracted his attention. Peering 'round the corner, his eye was met with a bleeding bundle topped with luxuriant curly hair. Sally.

"Golf Lima Gold Command to all units: urgent assistance and a medic required to the north corner. Sierra Delta One's been injured, currently semi-conscious."

Flicking the transmission button on his radio, Lestrade advanced, a strange feeling of unease creeping up his spine as he knelt beside her.

"Sally? Sally, open your eyes!" He was rewarded with a pained grimace and a flickering in her eyelids. "Sir?" She was slurring-he noted the crimson stain matting the left hand side of her hair at the temple-as running footsteps echoed through the surrounding gangways. Sherlock and John converged on them, John hefting his kit down from his good shoulder. Just as he did so, rapid gunshots began to ricochet off the surrounding metal boxes. Scooping her up into his arms and hunkering down behind the crate immediately to his left, John half-turned, yelling at Sherlock and Greg over the din.

"Find-ah, fuck, FIND HARD COVER! SHERLOCK, TO YOUR LEFT, GREG WITH ME!"

As gunshots and sparks flew past from Borthwick's stolen weapon, Greg scrambled into the shadows behind the container. He shivered as John's eyes met his. The gaze was unflinching navy and he shrank away as the shutters came down. He knew he was watching something quite rare, in John Watson's civilian life at least. The tunnel vision of war, a singular devotion to the task of keeping someone alive for long enough, had turned John's eyes from warm, twinkly windows into blank screens the colour of the desert night.

John reached out almost blindly, in a sequence he'd practiced so often he no longer had to think. He snapped on a pair of latex gloves, ducking without so much as a blink as streams of hollow-point bullets whizzed overhead. He gently touched two fingers to Sally's wrist, murmuring to himself and turning towards his bag. Noting vitals for pulse and respiration on a scrap of paper, he began to card his fingers through her hair and drag his fingertips over the scalp in a methodical check for bumps and depressions in the skull.

Finding a nasty cut along her temple, he nodded, running his practised fingers over her neck, back, fingers, arms, trunk, cataloguing every inconsistency and filing it away. He gently pressed on her ribs, finding a discrepancy. He soothed her, calm and steadfast, as she squirmed under his probing hand. Prodding the area, he reached across to his bag, pulling out a scalpel, alcohol swabs, a bottle and a hypodermic. Completing the setup with a narrow plastic tube, John looked across Sally and found Greg staring at him as he did so.

When John spoke, his voice was not his own. It was imbued with a heavy tone, authoritative and clipped. Although John seemed the type for stating orders rather than drill-sergeant screaming, Greg could see why they had made him a Captain so quickly. An odd whine in his ears shut everything out, the thought of disobeying never crossing his mind. All the considerable attention of the commanding officer was focussed on him as John spoke, low and deadly serious.

"Greg, pull her shirt up just past her stomach. Good, now use those wipes to clean around where that bruise is and sanitise your hands while I draw up the local. Hold that-" (he pressed a piece of gauze into Greg's shaking fingers)"-and hold her hand. Sally, this is going to hurt but you'll be able to breathe properly once it's over. Keep your eyes fixed on Greg." It was only then that Lestrade noticed, feeling slightly sick, that Sally had been wheezing badly. She arched away from John's gloved fingers.

His face hardened minutely, and he gently but firmly held her torso in place, slipping the needle into the intercostal space between the fourth and fifth ribs. Waiting a few seconds, he slid it out, deftly swiping the scalpel over the skin and digging the point into the cavity. He made soft shushing noises as she cried out, pushing his index finger into the incision. He pressed the tube against the gap, smiling grimly as an audible 'pop' and a hiss followed in quick succession.

"Better?"

Clammy and pale-cheeked, Sally nodded. Greg and John listened intently as Gregson, who had been over the other side of the dockyard, yelled at Borthwick to put the gun down. The tramping of boots heralded the arrival of the ARU.

"If you want me, coppers, I'm gonna take some of your lot with me!"

Moments later, there was a second volley from the murder weapon, which zoomed over a perfectly unconcerned blonde head and a cringing silver one. A single round from an assault rifle and the deed was done.

Wordlessly holding his hand out for the gauze, John quickly snipped a cut into the centre, with a hole in the middle of the square. He fitted it round the tube, taping it in place to stop it from shifting, and stood up in a fluid movement to rattle off a sit-rep to the paramedics. Greg hung back in a daze as they loaded Donovan into an ambulance, Watson jumping in without so much as a 'please'.

John's medical prowess hadn't escaped him, certainly, but the night's events had convinced him that he was dealing with someone still at the top of his game. What had shocked him, quite apart from the level of confidence and skill on show, was the brutal efficiency of the thing. John had become a completely new man, one who was obviously used to performing surgeries in the middle of a firefight or a bomb blast and thought nothing of it any more. Bullets had bent the air around them, whistling through the air as the sparks singed their hair. John had simply carried on, the stalwart captain in an urban battlefield. It had been fearsome to watch; he knew he wouldn't have wanted to be on the end of a beasting from that particular CO.

Greg checked his watch.

The whole process had taken five minutes, all in.