The Important Gentleman stood at the French windows in the military hospital, gazing out at the lawn. A young man in army uniform sat on the bench outside, the weak sunlight accenting the pallor of his features. He had a stick resting between his outstretched legs, his hands resting loosely on the top. His expression was bleak, blue eyes brooding. They've told him he won't fight again, the Very Important Gentleman guessed. Most soldiers who heard they wouldn't be going back to the front would have gone down on their knees and thanked God rather than looking resentful as though their bodies had somehow betrayed them simply by being human. He feels…dishonoured or some such, the Very Important Gentleman guessed. Interesting. And worth investigating. He opened the French windows and stepped out. "Captain Hastings?"

"It looks worse than it is, Captain. To be fair, you can hardly go dragging men back to base with a torn leg and then dig your fingers in the resulting mess and expect it to heal perfectly. You won't be marching on any more battlefields, I'm afraid."

The doctor's words echoed in my memory. Discharged with an injury; unfit for active duty. My fingers tightened briefly on the handle of my stick. It could be worse; at less I still have my leg. Unlike Wilson. Or Saunders.

"Captain Hastings?"

Startled, I looked at the man standing by the French windows. Something about his posture told me he'd been there for a while, studying me unobserved. He wasn't someone I knew and yet he did appear vaguely familiar. He didn't wear any signs of rank, and yet I was sure he was a military man, and of much higher rank than I was. "Yes, sir?"

He looked amused. "Just 'Captain', Captain Hastings; I'm of no higher rank than you." He gestured to the grounds. "Would you care for a walk?"

Whatever official rank he held, I was sure he was superior to me, so I gave a nod. "As you wish." I got to my feet, gritting my teeth against the flare of pain down my leg.

He started walking across the lawn and I matched my pace to his. Pain flickered constantly down my leg but I resolved to ignore it as much as possible, leaning heavily on my stick. In one way, his refusal to slow his pace in consideration of my wound was almost comforting. Since being admitted to the hospital all I'd had was sympathetic smiles and lowered voices, all saying the same thing: you'll heal, but right now you're of no more use to us.

"Wound painful?" He asked conversationally.

"Sometimes." Like when I try walking or resting it, or doing anything that requires the bloody limb to actually work."The doctors say it should heal sufficiently for me to be able to use it normally eventually. So long as I don't try to climb the Matterhorn or run a marathon." Or fight on a battlefield.

"It's to be expected." He said. He flicked me a quick, sideways glance, something almost sardonic in his eyes. "There was a suggestion of noting your heroics, Captain Hastings. Maybe by giving you another medal to add to your collection. Someone suggested promoting you to Major, but that seemed a little cruel given that you're about to be discharged."

"I see." I said shortly. Salt in the wound.

"I'm sure you do." He flicked me another of those amused sidelong glances. "Have you given any thought to what you'll do after leaving the army?"

I was tempted to ask what business it was of his, but instead I said "No, not really." My experience of the Styles affair with Poirot had proved to me that my dreams of being a detective were doomed to fail – I could help him find clues, sometimes notice things, but I couldn't make the leaps of intellect that he could to solve a case - and re-joining Lloyds held little appeal.

"You were involved in a murder investigation last year," he said, and I was startled at his thoughts running close to mine.

"Yes; at Styles."

"With your Belgium friend." He grinned suddenly. "Oh, don't look so surprised, Captain; we had to check he's what he appears to be and received positive reports from our Belgian allies."

"Indeed." My tone was wary; I wondered again who this man was and what he wanted.

"Indeed." He echoed. We'd reached the edge of the grounds and he stopped, turning to face me. "I'll be frank with you, Captain – I'm responsible for ensuring our apparent allies are just that – allies and not German spies or traitors."

I stared at him. "Why are you telling me this, sir?"

He seemed to consider me for a moment. "Because I'd like to offer you a job, Captain. It'll be dangerous work, frequently unpleasant, unthanked and probably underpaid, but important all the same."

"How do I know you're telling me the truth?" I asked.

"You don't. But ask for me here." He handed me a card. The address was in the Haymarket. He gave me his sardonic smile again. "Think it over, Captain. I think you're the kind of man we could make use of." He gave me a nod as he turned to walk away. "If it suits you, head to that address and ask for K. Any time."

Ten days later I presented myself at the address on the card and, feeling an absolute fool, asked for K. I half-expected to be laughed down the street, but instead one of the guards on the door asked me to wait and disappeared inside. I was wearing my service medal so was given a look of friendly respect by the other guard. "Been at the front, sir?" he asked.

"Yes. At Arras." Obviously his quick eyes had noticed the stick I was still leaning on. My leg was much improved, but wouldn't be completely healed for a while yet.

He whistled. "That was a bloody business."

At this point K appeared. "Captain Hastings." He greeted cheerfully. "Come in, come in." He led me down a warren of corridors, and I hoped I'd be provided with a guide to show me out again.

We came to an office and he gestured to a chair. "Take a seat." He moved to talk the chair on the other side of his desk.

"Thank you."

"How's the leg?" He asked as I leant my stick against the chair.

"On the mend. Hopefully I can dispense of this soon."

"Good. So, you've been thinking about my offer?"

"Yes, I have." I stretched my leg out. "Perhaps you could tell me a little more about it."

"Of course. We're a group of people interested in keeping the country safe, not by donning a uniform and matching onto a field but by keeping an eye on people we believe to be a threat and sometimes taking steps to neutralise them."

"'Neutralise' them?"

"Yes. Either by scotching their plans or, in extreme cases, by disposing of them."

"You mean killing them." I said flatly. We both knew what he meant, but I wanted it clearly stated.

"Yes. And not on a battlefield where people will congratulate you if you kill enough but secretly, in the dark, in a way that our government will strenuously deny if you're ever discovered." He leaned back in his chair. "Do you have a problem with killing, Captain Hastings?"

"I prefer not to if I can avoid it." I said truthfully.

"But you will, if necessary."

"Yes; I will." I paused. "I have." I said quietly. For a moment I felt the flare of remembered pain in my side – the bayonet, poorly aimed without any real force behind it in the hands of a boy in a German uniform. Blue eyes wide with fear, strands of baby-blond hair poking out underneath his helmet – he can't be more than sixteen – doesn't look old enough to shave, much less kill men on the orders of the Kaiser. His gaze is fixed, seemingly horrified, on the blood spreading across my uniform. The blade has sliced along the curve of my ribs, cutting through skin and flesh without piercing any of my organs. I want to tell him it's alright, he hasn't killed me, but the pistol's coming up in my right hand as though another mind is guiding it, tilted upward so the bullet will lodge into the brain under the pushed-back helmet. Droplets of blood strike hot in my face as the body topples backwards.

He wasn't the first or the last, but the memory of the wide, frightened stare was one that would occasionally jerk me awake at night.

"I have." I repeated. "It's not something I care to remember."

"I can imagine." K looked faintly amused again. "I'll be honest, Captain Hastings; I had your war records sent over to read through." He lifted a couple of sheets from his desk. "Captain Arthur John Munro Hastings – joined the Royal Fusiliers in August 1914 as a subaltern, first saw action in the battle of Marne that year. Served with 'quiet bravery' according to your commander," (I reddened) "promoted to Lieutenant; wounded at the Somme, sent home to recover where you investigated a murder with monsieur Poirot while doing some work for the War Office. Back at the front you were promoted again to Captain and probably would've progressed further up the ranks if you hadn't received your second wound that invalided you from active service." He looked up at me. "Dragging a couple of men back to safety with the muscles of your leg torn is quite impressive, Captain. But why did you dig your fingers into the wound?"

"I was passing out. I needed the pain to keep me conscious."

"Good lord." He murmured. "Well, Captain; are you interested in serving your country in a way that doesn't involve marching over a field?"

"I might be," I admitted. "But why are you inviting me to join this?"

He regarded me thoughtfully for a moment. "Because I think you have what we used to call the right stuff, Captain. And I do hope you'll forgive me, but you have the kind of blunt, honest face that means you can look innocent and trustworthy no matter what. We can teach you deceit, we can teach you charm and any skills you might need, but the ability to look friendly and amiably foolish is one you already possess. We can make use of that ability. So, will you join us?"

I could feel a smile tugging at my mouth. "If you know so much about me then you probably already know what my answer is." I said, offering him my hand.

He gave me a smile in return, clasping my hand in his. "I had a feeling, Captain, but it's always gratifying to be proved right."