Cormoran cursed under his breath as he rummaged through the chest of drawers, looking for his favourite thick woolen jumper. He tended to like it cold, but Yorkshire went beyond that to bloody freezing and as warm-hearted and welcoming as Robin's parents always were, they could never seem to block up the draughts that seeped through the windows of the spare bedroom.

He closed the top drawer and opened the one underneath: leggings, jeans, sweatshirt, leggings, leggings – how many pairs of leggings did Robin need for a three-day trip? Conspicuously absent was his jumper. With a resigned sigh, he shut the drawer and straightened up.

Maybe he'd left it in the sitting room? The house was quiet, but as Strike stumped down the hallway towards the narrow stairs he heard a soft, familiar giggle coming from the room to his left. He paused, and then, moving as quietly as he could, reached over to gently push open the door; but she must have heard his heavy footfalls coming down the hallway.

"Come look at Mummy," came the high, clear voice from inside the room; grinning, he abandoned his attempt at stealth and swung the door open.

Nora was perched on the window seat, face and hands pressed up against the glass as she peered intently out the window, her black hair loose and curling over her shoulders. Robin's younger brother Martin was standing beside her, arm braced against the wall and, like Nora, watching the scene outside the window with a delighted grin splitting his face.

"Why, what's she doing?" he said, stepping quickly to peer over his daughter's shoulder.

The window overlooked the front garden, dusted white with the snow that had fallen overnight; and there was Robin, muffled and gloved, her bright blonde hair peeking out from beneath her toque and - Strike squinted, then rubbed a bit of fog off the glass - wearing, instead of her own jacket, his missing jumper. She was halfway up the cobbled drive that sloped to meet the street, dragging a garbage bin that was almost as big as she was behind her. It took Strike only a moment to see what it was that had Nora breathless with giggles; the driveway was slick with ice that no one had salted, and while Robin's grip on the bin meant that she was able to stay upright, she was clearly having a great deal of trouble making it to the curb.

He watched, amused, as she shuffled slowly sideways, her free arm held stiffly out in front of her; she made it barely a metre before her boots lost their grip, and Strike couldn't help his bark of laughter as she slid helplessly back down the hill, hunched over the bin.

Martin leaned over Nora and banged the window open to shout, "Oi, Rob! Put it in front of you!"

Robin looked up; seeing three grinning faces in the window, she scowled and flashed them a rude gesture. She did swing the bin round in front of her, though, and began trying to push it towards the curb, but without success; she could only walk in place, her feet slipping over the ice in a bizarre parody of walking on a treadmill, making Martin and Nora howl with laughter. She paused, clearly thinking, and then began taking awkward, crab-like hops towards the gate. Strike was laughing now too, his cheeks aching as he gasped for breath; Nora and Martin started cheering as Robin neared the top of the drive, then gave exaggerated groans and shouts of encouragement out of the open window as she slipped backwards once more.

Finally, Robin seemed to come to an epiphany. She slipped and slid sideways across the cobbles to the small patch of grass that served as a lawn, where her scrabbling feet were able to find purchase. Her audience applauded and whistled as she turned around and trudged up the garden, dragging the bin over the ice beside her.

Though still chuckling, Strike felt a small stab of guilt. He'd have been even more useless on that ice with his one-and-a-half legs, so he couldn't have helped Robin if he'd tried; but so much amusement at her expense was hardly fair.

"C'mon," he said, grabbing Nora around the waist and lifting her off the window seat to set her on her feet, ignoring her giggling protests. "Let's go make Mum some hot cocoa, she'll be cold when she gets in."

The mention of chocolate drew her attention instantly, as Strike had known it would, and she trailed after him down the stairs, leaving Martin – still heckling Robin – behind them.

"Can I have some too?"

"Course you can," he said, reaching out to ruffle her messy curls.

"With marshmallows?"

"Would I make cocoa without marshmallows?" he demanded in mock outrage; Nora grinned toothily at him, her pale blue eyes – so much like Robin's – bright with excitement, then jumped down the last three steps and raced ahead of him towards the kitchen.

While Nora was distracted counting marshmallows into her steaming cup of cocoa, Strike slipped a healthy measure of whiskey into his own and Robin's mugs.

(Their daughter had recently developed an obsession with fairness, and any suspicion that the grownup's drinks were made differently than hers would lead to an argument that Strike would very much prefer to avoid)

With a gust of freezing air, the kitchen door banged open and Robin stamped into the room, her eyes sparkling and her cheeks and nose above the wool of her scarf bright red from the cold.

"You're both horrible," she informed them as she stripped off her gloves and hat, the static making strands of her golden hair stick to her cheeks and fuzz into a cloud around her head.

Strike grinned apologetically and handed over her cocoa; Robin wrapped her fingers around it gratefully, breathing in the steam before taking a careful sip.

"Thought that might make up for it," he said, as she hummed in appreciation.

"It's a start," she said, "but I think you'd better help me warm up." Placing the mug down on the table, Robin stepped into Cormoran, who wrapped his arms obligingly around her, and tilted her head up for a kiss. Her lips were cold against his, but her mouth opening under him was hot and tasted of chocolate and whiskey. Her hands were pressed against his chest as he drew her closer to him; and then, too quickly for him to react, she had slipped them down under his shirt to press her icy skin against the small of his back.

His curse was muffled against her lips as he jerked away from her freezing fingers; he broke the kiss to glare down at her.

"That's just mean," he said, though he didn't drop his arms from where they were wrapped around her.

"Maybe," she said, smiling wickedly up at him, her eyes dancing with mischief, "But so was laughing at me; now we're even."

"Fair enough," Strike murmured, as he reached back to grab her wandering hands in his before leaning down for another kiss.

Nora sighed loudly. "That's disgusting," she said, with all the dignity that her six years could muster, and then, "I'm going to play Mario Kart with Uncle Martin."

She marched out of the kitchen and Cormoran, grinning, slid his mouth to press against the skin behind Robin's ear.

"Did you hear that?" she murmured, her fingers curling in the hair at the base of his neck. "We're disgusting."

"We could go be disgusting upstairs," he muttered into her hair, dropping his hands to her arse to pull her more firmly against him and silently blessing her obsession with leggings as he did so.

"Later," she said, pulling away with a soft smile and a promise in her eyes. She dropped a final kiss on his lips and stepped out of the circle of his arms, ignoring his groaning protest. "I owe Martin an arse-kicking in Mario Kart."

He watched Robin pick up her cocoa and walk out of the kitchen, admiring the flush of her cheeks and the curve of her thighs emerging from beneath –

"Hey, that's my bloody jumper," he shouted after her, "you're giving that back."

Her laughter trailed behind her, and Strike sighed in resignation. He wasn't going to be getting the jumper back, he knew, but as he sipped his own rapidly cooling whiskey and cocoa and went to join his family, he couldn't seem to bring himself to regret it.