"All right, wee man?" asks Morna as she pushes the pushchair up the steep incline at the top of Leith Walk near John Lewis. Her head down, she strains to push the creaking plastic and aluminium contraption. She has the sexless figure of a pre-teen but the gaunt face and the bony fingers suggest a grandma.

         "You're getting big. Look at you."

         Colin gurgles and babbles, and only the word 'Ma' is distinguishable.

         "You'll be having your birthday soon. I'll bet they'll have a cake for you with two big candles stuck in the middle." She pauses to catch her breath and wipe her watering eyes. She shakes the ache from her limbs. "And, I'll send you something nice. What'd you fancy, Eh?"

         "Ma, Ma, Ma," says Colin. He cries and thrashes. He barely fits the seat, and the pushchair bounces with his movements. At the end of his fleshy legs, white trainers like unbaked bread loaves dangle. It takes all her strength to heft his bulk onto her hip. He's already a third of her size. His elbows are dimples; his joints are seams connecting one buttery mass to another. A tuft of blonde hair sprouts from his head. Breakfast stains streak his green and white Hibs shirt.

         She looks into a shop, past the phone card advertisements, and eyes the cigarettes behind the counter.

         "Not today. We've your snaps to buy," she says to Colin. A young man with a shaved head and black smudges for eyes steps from the shop. He looks up and down the pavement.

         "Hiya, Pal." She puts two fingers to her mouth and points to his cigarettes as he packs them against his palm. He rolls his eyes but holds the pack out to her. He hands her the lighter. With smoke pouring out with the words, she says, "Cheers, Pal. It's my boy Colin's last day. We have an appointment -"

         He walks away.

         She thrusts forward the pushchair to cut a path through the Prince's street crowd: doughy American couples in matching raincoats, businessmen that check their watches against the one o'clock gun and listless teenagers cluttering the pavement in cackling groups. After two sharp turns, one right, one left, she drives down Rose Street, weaving between the meandering pedestrians, nearly wheeling over their feet.

         She rings the flat. The speaker crackles.

         "Hello?" asks a sleepy voice.

         "It’s Morna. Colin's ma. The snaps done?"

         "Aye." The door buzzes.

         "Can you help me get Colin up the steps?"

         "Hold on."

         In pyjamas and a bathrobe, the bearded photographer's bones creak at each step down. He grabs the front of the pushchair and Colin kicks at his hand.

         "Stop that! Stupid boy." She taps him hard on the head. His hands shoot to cover himself. He gives a few more kicks as the photographer moves his hands to a safer spot near the pushchair's wheels. The steep stairwell rings with Colin's huge wails.

         "Slow down, Pal. I can't keep up with you," Morna shouts.

         The living room is covered in a white sheet. A camera on a tripod, its one eye shut, waits for someone to step before it. Colin watches it, wary of movement in its spindly black legs. The photographer hands Morna an envelope. She takes it and sits on a couch.

         "You smoke?" asks Morna.

         "No."

         "Ah, they're ace. My handsome wee boy. Look at you Colin, big man." She dangles his photo in front of him. In it he is wearing his Hibs kit. It is spotless. He is staring with open mouth surprise at the camera's beeps and flash. She is beside him in a matching outfit. She is wearing eyeliner but no lipstick; she couldn't find any. Rather than the dry bundle of straw at the back of her head, her hair is draped over her shoulders, shining and freshly washed. She is joy. She is bliss to have the photos being taken, to feel his soft, warm hand on top of hers. "Cheers. They're brilliant. They really are." She slides the photos back into the envelope, hands it back as she kneels before Colin to retrieve the money.

         "Ma, Ma, Ma."

         "Too right. I'm your ma. Always will be. Did you keep Ma's money safe? Make sure she didn't spend it?"

         "Ma."

         She pulls off his trainer. He waggles the socked foot at her and tries to touch her cheek. She reaches into the shoe and retrieves thirty pounds, warm and moist.

         "Sorry, but it's thirty for the session and thirty for the prints."

         "That's not what you said."

         "I'm afraid it is." He pulls a receipt from the envelope and hands it to her. "That's your signature."

         "Fucking hell, Pal. I need them today. It's our last day together. I'll pay you tomorrow."

         "Sorry," says the photographer, afraid to move the envelope in his hand as she stares at it.

         "You're not sorry. I'll be back with your money," she says still looking at the envelope.

         "I have to go to work at five," says the photographer.

         "I'll not be long," she says and steers Colin toward the door.

         "Shall I help you down the –"

         "No. Down's easy. You just stay put. I'll be back."

         Her body aches. The bones in her legs vibrate pain. She darts towards the Prince's Street Marks and Spencer and their tills.

         Colin squeals at the faces zipping past. She moves too fast for the automatic doors, and he jerks forward from the impact, still giggling. She sidles up to the end till as the blond pony-tailed girl takes a twenty from a customer. Morna watches the tray, stuffed with bills, yawn open. She feels the girl watching her.

         "Is Mikey working today?" asks Morna.

         "Taking a break." The girl nods towards the back.

         Mikey sits smoking on the step to a massage parlour. He looks up to see his mum and his half-brother wheeling toward him.

         "Hiya," he says, wiping his palms on his trousers.

         "Give your Ma a smoke."

         He hands her one.

         "Ta."

         "Ma. You alright? You're sweating?" he says, still rubbing his leg.

         "I'm fine, fine," she says.

         His shoulders slump forward. He takes a deep breath and prepares the question, "Are you using again?"

         "Big man now. Aye, seventeen, on your own. Know the score, the ways of the world, do you? Well, for your information, I'm not. I go to the clinic every morning for my jellies. I'm just stressing. It's Colin's last day."

         "Okay, Okay," he says.

         "I need forty quid…Don't give me that look. It's not for me. It's for your brother, not me. For his snaps."

         "It's all I got," he says and hands her ten pounds.

         "Do you remember when we had your snaps done? When they took you?"

         "Ma. Please?"

         "Ma, Ma, Ma," Colin gurgles at Mikey who leans in to rub his fat baby cheek.

         "Can you borrow the rest from the till?"

         "It's fucking Marks and Sparks. They have cameras and shit."

         "Can you ask your mates?"

         "Ma," he pleads.

         "Ma, Ma, Ma," Colin sings.

         "Then I'll go over to Iain's flat. He owes me."

         "Iain owes you money?"

         "Yeah. Look at you with that face again. What'd you know about it?"

         "Nothing. Just don't go over to Iain's, please. I'll use my overdraft."

         "You got a bank account? You really are the big man." Morna smiles with pride at her Mikey. "My Mikey."

         "Yeah. You have to have one. That's how they pay you."

         "We need to make a stop before we pick up the snaps," she tells Colin as she hurries away from Mikey and the cash machine. "You should see your Daddy Iain before you go to the home." She formulates a thousand silent promises to herself, Mikey and Colin to bridge the space between Princes Street and the Cowgate. She doesn't give herself time for all the reasons why she shouldn't knock on Iain's door.

         Inside his flat, her body stops punishing itself and calms in anticipation. The flat is damp and cold, hidden in the shadow of South Bridge. A maze of couches and sofas crowd the small room. A once blue sofa, now a dusty grey, blocks the hallway to the rest of the flat, a bedroom and a bathroom. Two torn black leather couches stand length-wise in the corner like ancient menhirs. At the centre, two white sofas face each other almost touching. Morna sits on one, Iain opposite. He's the same size as her. Since going bald he keeps his blonde hair shorn close. He looks desiccated. His bottom lip has a scab like two dashes of Morse code. He picks at a burn hole in the armrest. Colin sits beside him and draws on the couch with the charcoaled end of a burnt match.

         "Don't you worry. He won't be gone as long as Mikey. That was different. They have rules now, new laws, and I'm not going away like Mikey's Dad. You'll move in here. We'll clean up the place. Have the social workers over. They tick the boxes and Colin'll be back home in 90 days," says Iain. "I'm telling you, Claire and Riggs did the same for their boy. Riggs sorted it all out. 90 days max, I'm telling you."

         "That's not what the social worker said."

         "One second. I got Colin a present." He climbs over the couches and disappears into the darkness at the back of the house. He returns with a nylon net bag full of wooden alphabet blocks. "Had these at Lidl's. Couldn’t resist." He strains to pull the net bag open then showers the blocks in front of Colin who sits back surprised. His mouth, cheeks and finger tips are smudged with charcoal. Iain hands the 'M' block to Colin, who scratches at the yellow lettering with an unlit match.

         "You too, Ma. You don't need to be sad today," says Iain. She takes the folded paper packet and soon the world goes white and warm wrapped in Colin's clacking of blocks and his chants of, "Ma, Ma, Ma".

         A question raises her from the drowsy, gentle rocking of the chemicals. "What time is it?" she mumbles. Iain is gone. Curled under her arm, Colin sleeps. His warmth makes it hard for her to move, but there is something nagging her. She is missing something. Something needs doing. The snaps. The appointment.

         Her body moves automatically. She loads Colin into the pushchair and he continues to sleep in the misty drizzle as she races the clock's minute hand, staring down at her from the Balmoral Hotel, towards five o'clock.

         The button beside the photographer's flat number gives a long heavy buzz beneath her finger. No answer.

         Zzzzzzz. No answer.

         Zzzzzzz. No answer. The door opens.

         "I thought you left," she says and holds the thirty pounds at him. He hands her the envelope.

         "I am now."

         She catches the 22 bus. Its windows fog from the tightly packed and sodden passengers.

         "He's a handsome lad," says an elderly lady, leaning over to see the photos.

         "He looks just like his Daddy," Morna says to the sleeping child in the pushchair.

         "Here dear. They put these through the letter box this morning. It's a voucher for the Waterworld. You know, by the Scotmid. The boy'll love it. What's the matter, dear?"

         "Nothing. Just tired. This is my stop. Ta for the voucher."

         She turns onto her street near the bottom of the Walk and behind the old charity hospital, which has been turned into posh flats. Two men are standing by the entrance to her building. They radiate signed forms and neutral apologies of government sanctioned officiousness. She tries not to make eye contact and aims Colin towards the gap between them. As she draws closer, they step towards her.

         She utters a weak, "He's my boy," before the tears choke her voice.

         Colin says, "Ma, ma, ma," to the men.