It was in the McDonalds on the high street where I first laid eyes on the couple. Neither of them struck me as scruffy. He was wearing a clean tracksuit, trainers, baseball cap and she in tight denim leggings, trainers and a white jumper. What I found unusual was that they were carrying lots of carrier bags that appeared to have things inside them. Not that unusual, you might think, silly old sod you may well say but when you realise that it was merely 08:30 hours and the shops hadn't even opened the doors to let the staff in yet I think you can guess where my train of thought was instantly led.

I've done enough of modern day policing to recognize a couple of shoplifters when I see them, not the old kind, the new kind, the heroin kind. It was both of them as well, him more than her I guessed. It's usually that way round and that's a fact, no getting away from it. Boy meets girl, girl falls in love, boy introduces her to heroin; I've seen it so many times. Before long she'd be sucking his drug dealer's dick to pay for their habit, she'd probably have to make him come quick before her boyfriend smoked the lot as well.

I watched as he ordered two coffees before he turned round to sweep the place with his eyes. I dropped mine, hoping that my old man façade would put him off. Not that I'm in disguise or anything, it's just that old people are generally not registered by the young, the young are only normally interested in sex. Normally, because there are some who are on the alert for other things, like people following them for example, whether the CCTV cameras are following them or not, things like that. As I suspected his eyes only stayed with me for a very short time, only long enough to register the grey hair sticking out of my hat. Forgot to mention the hat, I wear it all the time these days, a brown trilby to cover my receding hair. Not that, for a man my age, I haven't done well in the hair department. There I go again, telling you needless facts, you want me to get on with it don't you.

The couple took their drinks and walked around a stop sign to get to the upper level. It clearly didn't bother them that the stop sign was placed there for a reason. I looked around to see if anybody else had witnessed it and the three other customers that were in there were only interested in their food. I did notice that one of the members of staff had seen, she looked at me and shook her head as if to state what can you do, I just work here. She's entitled to her opinion of course, but you know me, I've never been one to sit by and let things happen. Not criminal things, just cause I'm retired don't mean I've got to stop being an upstanding, law-abiding citizen.

I picked up my coffee, after a correct pause, and headed up the stairs after them. I couldn't see them as I reached the top of the stairs, and even once I had sat down and had a good look around I still couldn't see them. I looked around again, keeping my head down; you never know I might have missed something. I hadn't, they weren't there, which of course was impossible, there is only one way out and there's no way they could have left without my seeing.

I quickly came to the conclusion that they were in the toilet, maybe it was a coincidence and both of them needed the toilet at the same time, or maybe they were both in the same toilet taking drugs. Chasing the dragon, or maybe I'd walk in there to find them both dead, a dirty syringe hanging out of one or the others overworked veins. It didn't happen of course, I mean they were both definitely in the same cubicle. I heard her giggle, as I entered, not the place to hear a female giggle.

I pulled out the old fella and leant against one of the urinals making as though I belonged. I stared at the tiny urinal, the one they have there for the toddlers, while I strained my ears to catch any sounds coming from the cubicle.

"Come on." She begged. "Give me some." Then a long pause, the sound of a lighter beneath tinfoil, the sound of smoke as it is sucked through the tube and into the lungs. Another pause and I imagine them as they hold the smoke in for as long as they can before exhaling it with something akin to ecstasy. I didn't know which one it was who was smoking it till I heard him say.

"No." his voice firm, definite. "What you told me this morning? No way, fuck that."

"Euuuugh." A stupid whining sound that emphasized her discontent. "We don't know yet."

"That's not the point." He said. "You've got to get off it."

"Oh and that'd suit you just fine wouldn't it." Her voice irritated. "What about you? What about you giving up?"

"You've got an incentive, it's easier for you."

"That's bullshit. That's fucking bullshit and you know it!" Quiet again as the lad draws on another line. I could actually smell it then, a sweet sickly scent that you could never imagine knowingly inhaling. The smell was so pungent that I very nearly threw up myself.

"You ready then?" his voice. The latch went on the cubicle door and I turned to the side so that if they looked at me they would only see my back. "You're not supposed to be up here mate." He said, laughing as the two of them left the toilet. I resisted the urge to turn round, waiting for the toilet door to swing closed before putting back the old fella and following after them.

I must admit that I found my new adventure quite exciting, it had been some time since I'd done anything worthwhile. Catching these two would certainly make me sleep easier for a while that's for sure.

As I suspected they intended to hit the high street, their first point of call was Boots the chemist. I walked in not long after them and observed them standing in the aisle that stocks the cosmetics. I walked past them, beneath his hidden stare. He was good all right, clocking everything without the need to look for too long. Swiveling he was, and pacing this way and that while she loaded up the carrier bags with make-up. I could see them quite clearly from the baby food aisle.

"Any help sir?" a friendly shop assistant. I thought about telling her of the unwelcome guests in the make-up aisle but something, don't ask me what, made me decide to wait for a bit. Maybe it was because I was interested in finding out whom their buyers were for the stolen property, or maybe it wasn't anything to do with that at all. I told her politely that I didn't need any help, and it wasn't long before they both left the shop.

I followed the two for the best part of an hour as they hit all five chemists on the high street. Their mood had changed and there was a certain spring to the step as they entered McDonald's once more. They were trapped, I could have phoned the police right then, and with my statement they'd have no way of getting away with it. I didn't do that; I followed in after them instead. Once inside I couldn't see them on the ground level, so I went upstairs to use the toilet again.

They were in there; I could hear raised voices as I opened the door. They didn't hear me come in, not that they could care less anyway I imagined.

"Don't you dare." She said her voice heavy with warning. I got to the urinal and pulled out the old fella, this time for legitimate reasons.

"I need to." He almost whines.

"If I'm stopping then so are you." Her tone assured, definite. "We're both going to look after this baby."

"I thought you weren't sure yet." A pause, the statement treated as a question.

"Well I am now. I'm sure." She pauses again. "And I need you. I love you. We can do this I know we can. We'll be strong for each other." A slight chuckle, his.

"Okay, okay." He relents. "You can have some. Just stop fuckin' goin' on."

"NOOOOOO-UH!" the rage in her voice unlike anything I've ever heard. "Are you fucking listening to me? I'm pregnant with our baby."

"Well why the sudden change now? You were gagging for a bit earlier. What's happened now?"

"It was you who said that I should stop." She tells him; her voice calmed somewhat, maybe because she thought someone was listening.

"Yeah you, not me. I'm gonna stop as well, just not yet."

"Not yet?" she raises her voice again. "When then? Just listen to this yeah. If you don't throw that shit away right now I'm leaving. I'll walk away from you right now."

"You wouldn't do that."

"Just you try me." There's a pause. "Please don't. I mean it. There's something inside of me now that is much more important. I don't give a fuck about any of this shit anymore. It's just one big nightmare of a circle and I'm getting out. I'm getting out now." She pauses again; there's the sound of tin foil being smoothed, a lighter being lit as he prepares the foil. "If you do that now, then we're not together anymore. Please don't, I don't want to be on my own." The sound of nothing for a while, and then. "Fuck you then!" The cubicle door swings open and she storms out.

"Okay." He shouts. "Okay." But it is too late as she has already left. He chases out after her and when he has gone I take a look in the cubicle and there it is, on the scuffed tiled floor. A square piece of tin foil creased at one edge and inside the crease a small amount of grey powder. It used to be brown in my day, a lot weaker back then and a lot more expensive too. I didn't want to leave it there where anybody could find it so I tipped the heroin into the toilet and flushed the chain. I threw the foil in the bin then headed outside to see if the young couple was still about.

I noticed them right away; he was pinned against the wall by two members of staff from the local Greggs. I remembered that they'd stolen some sandwiches from there earlier to eat before raiding the next chemist. She was standing next to him, crying.

Well you'd have thought that would have been it wouldn't you. What more could I do? They'd been caught. What I did next dear surprised even me. I walked over to the two members of staff and told them that the young man was my son and that I'd be happy to compensate them for any inconvenience caused. They clearly weren't happy with the idea but when I told them that my son suffers from mental problems they relented and accepted ten pounds each to forget the whole thing.

"Why?" the young man asked me.

"Why?" I answered. "Because once I was just like you. I had the choice between alcohol and my wife. I picked the right one too." They smile at each other and in that smile I see that I did the right thing.

"Are you still together?" she asked.

"We'll always be together." I answered.

So dear, I hoped you enjoyed listening to my eventful day. I'll just put you back on the mantelpiece. I know you'll think I did the right thing. What was that dear? Oh right, goodnight. I love you too.