One sentence that I came to be very wary of was this one: "Can you do something for me Jonny Jonny?" From anyone in my new "adopted" family it was never good news but when it came out of the boss's mouth, it was enough to get your breakfast sluicing around in your stomach like even it was looking for a way to abandon you to your fate.

"Jonny Jonny," he said this one day, "Can you do something for me, Jonny Jonny?"

He was sat at his desk, some grand, ornate thing with insets of gold and pearl. It was covered in paperwork: a litter of letters, mostly hand-written, takeaway menus and half-used up prescription pads. His words came from between crunches that I knew, for the time of day and the waxy glaze of his eyes, said he was chewing on a spectrum of rainbow pills like they were candies.

"Sure boss," I said because, nausea or not, I wasn't stupid. A lot of Joker's talk is phrased like questions but there's rarely more than one right answer to any of it.

I wondered, naturally, what it would be this time. By this point in my career I'd done a lot of somethings and they'd spanned from murder, hostage taking and robbery to simple threats, getaway driving and form-filling when boss was too high to figure out which end of a pen should be facing downward. Hell, the worst time I remember I had practically pissed my pants at the guy's tone only to get asked to go on a coffee run – black, very very black Jonny Jonny. Maybe a Danish too.

This one was new but I guess, in hindsight, I should still have seen it coming: we had a new member to our fucked up "family" this month. As far as I could make out she was some blonde whore who worked out of one of Joker's clubs, though she insisted she was also in college. Spending any short while around the boss said that he saw something completely different to the rest of the world when he set eyes on her: she was Helen of Fucking Troy, Mona Fucking Lisa, Cleo-fucking-well, you get the idea. Joker's happy combination of drugs and sleep deprivation had shown him some special side of the gal that the rest of the world, with naked eyes, totally failed to spot. Though, I will say this much for Harley: she did have the prettiest blue eyes of any whore I've ever seen. And she had a certain class that most of them lost after a week of getting sweat soaked dollar bills slapped on their asses. If you'd seen Harley in her civilian clothes, striding down the street, you'd have guessed she was a socialite, not a stripper.

Joker had carefully reached inside the inner pocket of his trench and extricated, carefully between the tips of gloved fingers, a page from a magazine. He unfolded it on the desktop, attention fully focused on smoothing over stray creases before he gave it a tap and found his voice.

"You know what that is?"

Not being a fag or a woman, I could get no closer than "a coat". Sure, it looked alright I suppose on the wafer thin model wearing it in the catwalk shot. It had a big swoopy collar, was pitch black with a blood red lining. It'd keep you warm and it'd have gotten stolen in a split seconds in the Narrows. It was alright.

"No, can't say I've seen those before Joker," I said. I liked to give him the opening for a joke, the opportunity to rib, if I could ("It's a called a "coat" Jonny Jonny"): it kept him sweet. Today, though, he was all business and his mood stayed flat and serious.

"S'Prada," he chewed on the word, making it sound more like a brand of automatic gun than of luxury threads, "It's…well," he tapped the photo again as though to explain, "I need one."

I guess when you work for madmen the urge to laugh at idiotic times grows on you, you witness it happen often enough. I'd also witnessed people being clubbed to death with club furniture and drinks bottles enough to know that it was a temptation best resisted. Still, it was tough, you know? Joker had come to take a shine to me, you see. Maybe he saw me as a brother, or a son (never quite figured out if the guy's had a hard life or if he is getting on in years). Maybe he just liked that I was one normal guy among all of his brain-dead clowns.

Whatever it was, I saw more than most he kept around. I knew he would be wining Harley, smooching on Harley, simpering over Harley and then, wham, with words or a just a look she'd stop him dead. No more tonight. No go, no fly zone. Like a fucking sledge hammer to the guy's heart. The bitch was cold, maybe even a little clever or at the very least as bold as fuck. The times when I saw her push aside his nuzzling kisses, like a pig on the hunt for truffles in the vicinity of her chest, I thought maybe she was smart enough to study to be a shrink. Anyone else would have wound up in a body bag long before our Harley.

So, I didn't voice it but I knew why the boss needed a woman's Prada coat. There was even a sheepish squirm to his shoulders as he tapped the top corner of the magazine spread – a sloppy, feminine hand had written "Size 1 puddin'! LOVE YOU!" in fountain pen. I offered a weak smile and a nod of understanding. It was bad enough that a man who was skinning his way back to the top of the mobster food chain was begging whores to touch him, he scarcely needed to ask his boys to get this coat in this size and oh, do get the matching handbag, it's delightful – fucking sad, right? I just nodded my understanding and we were done.

"There's none left at any department stores," Joker spoke up when he'd folded the magazine spread back away and into the pocket over his heart, "I've looked, I know. You're going to have to get creative this time Jonny Jonny. Can you do that for me kid?"

"Sure I can boss."

And I did. I mean, I went fucking private eye for that jacket. I'd lingered outside all of the swankiest restaurants, all the mobster affiliated places and kept a look out until I'd seen the stupid opera-looking coat on a girl Harley's age. I'd found out who she was from a bribe to a maître d'. Then, then I'd try to barter with her. Bad idea. The blue blood had laughed in my face and I'd gone back to the boss, tail between my legs.

"What?" he'd asked over a plate of grey hot (probably pigeon) wings, one of two dishes served by Grin and Bare It when the chef wasn't busy stomping on cockroaches.

"She wants 50k for the coat, boss."

He finished working a slither of grisly flesh off a sickly yellow bone with those shark teeth of his then, with a mouth still glistening with grease, he repeated his question, irritated. By the bar, I could sense that Harley was listening intently, even if she was making a show of applying her lipgloss.

"50k. Says it's a good coat," I mumbled some shit about alpacas and hand woven, all the bullshit the bitch had flung at me. Joker listened, intently but pissed.

"Jonny Jonny, you've not learned anything about business yet, have you?" he muttered before getting heavily to his feet. He patted his pocket, maybe checking for car keys, probably checking for his gun. He sent a doe-eyed look towards the bar and his Harley. After a minute, the girl graced us with her attention (I could never tell if she was toying with him or if she was just so slow it took her that long to notice eyes on her). She hopped from the bar stool, abandoning her tube of lipgloss on the counter to come and stand by Joker's side. He placed a creaking, leather-clad arm about her only for the girl to let out a bleak little noise, apparently meant to sound happy but more like a bike with a puncture, sighing.

"You need to see this, Mrs Napier," Joker told the girl jovially, "S'important."

I caught a mumble of something coming from Harley, whispered, to Joker's delight, directly into his ear. Whatever it was caused the man to throw me another set of car keys.

"Taking the Porsche Jonny Jonny."

And we did – man that car was a wet dream, handled like it read your mind, even if it did have the police watching us like hawks the whole way. We wound up at this penthouse just past midtown. Joker did the honours of shooting out the lock and scaring the fuck out of the patron. She'd gone to press the panic alarm but he waggled his gun at her to show how that really wasn't in her interests.

In a lot of ways the girl was like a Harley born into money and class. Harley had clearly worked hard to get her hair so nice, her skin so clear – this kid, not much older than Harley herself – had never known different. Weirdly, it was obvious on one look to the boss that he didn't see the similarity, didn't think of swapping Harley Mark 1 for a better model. And trust me, boss could have had her. It's true what they say, you know. It's the attractive guys and the funny guys who get all the girls. Even more so when the funny guys have money, psychoses and guns.

"Need your Autumn/Winter 09/10 Prada coat," he'd said, bluntly, "Noone gets hurt."

The girl's education had been good enough that she didn't barter, didn't challenge him but just ran to her bedroom after he had given an authorising nod. Again, I'd had to fight down a laugh at the joyful grin Joker had sent a bored, texting Harley, as though the blue blood was a shop assistant heading in the back for stock.

When she'd returned, Harley had finally glanced up and the hint, the very suggestion of a smile had graced her lips. Joker looked like he might have died of delight at the expression. And that's when I really didn't know whether to laugh or cry:

Joker, absent-mindedly, shot the blue blood dead. He hadn't even looked at her, just squeezed the trigger of the gun still pointing at her. Both he and Harley had stared, horrified, at the sound, at the small explosive snap of the bullet flying straight through the woman. They had rushed to her side and both had had the same concern in mind: the Prada coat! The poor, poor Prada coat!

Joker had been quick to snatch it from the gurgling, groaning woman and thankfully, there had just been the slightest of blood fleck the blood-looking silk lining. He sighed with relief and walked out of the apartment, leaving us to trail him. Harley was at his side, like a hungry animal, dogging his steps. He kept the coat clutched, carefully, not bruising it, in one gloved hand as he opened the doors for the lift.

"See, Mrs Napier," he told the girl solemnly, gesturing with the coat. It was kind of disgusting, seeming them then: the way he knew how she wanted it and how he taunted her with it, waggled it, enjoyed his one moment of keeping her full attention. But then they were never a couple to model your marriage on, "This is what I'll do for you."

When she looked like she was going to text again, he made to crumple the coat. I suppose it was the equivalent of a teacher saying "What do we say?" to an obnoxious child they had just given a treat.

"Thank you," she purred. We rarely heard Harley speak but there was no denying: she had a cute voice, sugary and seductive, "Thank you sweetie."

And with that, any other efforts to scare the girl, to put her in line, left Joker's mind. You could see in his face how he was just happy: ecstatic. His heart flooded up into his eyes and made them glow like he was, well, alive for once. Most of the time you'd struggle to know whether he was alive when he was dosed. I'd walked in more than a few times to find him, deathly still and wondering whether I should check for a pulse.

She slid over to him, the one or two tiny steps between them in the lift and kissed him. I mean actually kissed. They shared pecks but this was possibly the absolute first kiss they'd had. She was always ducking his hands and his lips, leaving him looking more like a kicked dog than a man capable of running an entire state with an automatic and a smile. I ducked my head but there were still the tell-tale sound of pleased grunts, tongue, salivia, an opportunistic groping hand and a polite murmur of "approval" at the route taken by the hand.

It's a testament to their fucked up relationship and how much he must have – hell, why not call it what it is – loved her that he didn't just shoot her on the spot for what she said next.

With a glossy, lipgloss covered pout she smiled, for the briefest of moments, taking the coat from his limp grasp.

"Thank you sweetie," she purred. And then she pulled just out of his reach, donning the coat (it looked fucking ugly), "But next time, no second-hand hand-outs, puddin'," and she'd flicked distastefully at the minuteness, most pin-pricked sized drop of blood on the lining.