"Son of a bitch!"

Dean threw the long piece of particle board into the corner of the room and let out a frustrated snarl. At the desk, Castiel looked back at the large sheet of paper in his hand and frowned slightly. "It says here that you need to insert tab 3 into slot B," he said for the third time, with some uncertainty.

"I know what it says, Cas!" Dean snapped. "But what it says on there -" he waved a hand at the instruction sheet "- is not what I'm seeing here, OK?!"

A wounded expression briefly flickered across the angel's face, but was quickly replaced by a look of annoyance. "I don't know what you expect me to do, Dean," he said testily.

For a split second, Dean considered pointing out that Castiel's brother had been able to create entire realities from nothing and that, had he done something similar, Bobby would already have a shiny new bookcase and Dean would be on his third well-deserved beer. He caught the hard stare that Castiel was giving him, however, and thought better of it.

He exhaled sharply, ran his hands through his hair irritably, and strode over to the corner of the room to retrieve what may or may not have been one of the shelves. It shouldn't be this difficult. After all, he had fixed up the Impala countless times without any trouble. Then again, the Impala hadn't been issued with a set of instructions and diagrams that Dean could only assume had been written by somebody suffering the after-effects of a blow to the head. He had heard it said once that IKEA instruction sheets were products of the darkest depths of Hell and, based on his professional and personal experience, he was inclined to agree.

He crouched down and, as calmly as he could, scrutinised the array of components in front of him. It had been his fault that Bobby's old bookcase had been broken (Dean's last birthday celebrations had been a much more raucous affair than usual, and after countless glasses of bourbon a well-intentioned martial arts demonstration had quickly gone awry), so it only seemed right that he should be the one to replace it. True, a hastily-chosen piece from IKEA was hardly as good as an old solid-wood masterpiece, but it was the best he could do. As he looked back over the previous hour's work, he couldn't help feeling that the punishment had far exceeded the crime anyway, so Bobby would just have to like it.

Castiel watched him working with mild interest. He had to admit, he was more than a little confused. When Dean had tossed the folded piece of paper to him, he had been under the impression that this had been a request for his assistance. However, so far every time he had read out one of the directions, they had been met with surly remarks, so now he was a little unsure of what his role in this endeavour was exactly. Sam would probably have been much more help in this situation, he reflected, but the younger Winchester had obviously sensed the impending storm the moment Dean had walked through the door with the box, and had made a swift exit muttering something about research. Castiel briefly considered forcibly bringing him back to help, but decided against it. He had had the expression 'too many cooks spoil the broth' explained to him and, while he wasn't entirely sure that the ins and outs of cookery were the same as those of the furniture building process, he was fairly certain that the general sentiment of the phrase could be applied here.

"Alright, you flat-packed whore. This ends now."

Castiel looked up to see Dean standing over the half-formed monstrosity, brandishing a screwdriver threateningly. A faint smile played across his lips – there was something that vaguely amused him about the extent to which Dean could get so worked up about such trivial matters.

"Cas, come here and hold on to this," Dean said, gesturing towards the bookcase. Castiel stood up and went over to crouch beside it. Dean reached over and braced the side edge of the case against his assistant's leg, picked up a board from the pile and lined up the tab on the short edge with its corresponding slot – predictably, the tab was a millimetre or so wider than the slot. "Now, hold that," he instructed, tapping on the board, and Castiel obliged.

He eyed the unstable arrangement critically. "That's not going to fit, Dean," he stated matter-of-factly. "The craftsmanship here is very questionable," he added after a moment's consideration.

"Yeah, you're telling me," Dean muttered. He placed his foot gently on the edge of the plank, and in one fluid motion brought his leg up and then slammed his foot back down against the board. With a resounding crack, it split cleanly in two.

Castiel glared up at him, his expression practically screaming 'I told you so'. Dean pointed a warning finger at him. "Don't you say a goddamn word," he growled.

Castiel narrowed his eyes. "So what do you intend to do now?" he asked, his voice laced with exasperation.

Dean turned away and placed his hands behind his head, looking up towards the ceiling. He stood there in silent contemplation, while Castiel watched him closely. Minutes passed. Finally, Dean threw his hands up in the air with a soft cry of "Ah!" He leapt over to the desk and began rummaging frantically through the drawers. Finding what he was searching for, he looked up at Castiel, grinning. "We ain't beat yet, Cas!" he exclaimed triumphantly. "Hand me those pieces."

It was approaching 6pm as Sam arrived back at the house. On reaching the front door he paused, his hand resting on the handle. He steeled himself – he didn't know whether he'd be called upon to console or congratulate, but he wanted to be prepared for either eventuality – and opened the door. The house was silent, and he honestly couldn't tell whether that was a good sign or not.

"Uh... guys?"

"Hello, Sam."

Sam made his way through to the study, and surveyed the scene before him. Castiel was seated at the desk, a pile of torn pieces of paper scattered at his feet. Over on the couch, Dean was fast asleep, an opened – yet full – bottle of beer held loosely in his hand. Sam gently took it from him and took a sip. "So," he asked "how did it go?"

"It was... eventful," Castiel replied, his tone giving nothing away.

Sam looked around. "So where..." he began. Then he saw it. He had to admit, they'd done a pretty good job. It was certainly recognisable as a bookcase, which was a good start, and even looked like it could fulfil its function. His gaze came to rest on the top shelf, the middle of which was bowed downwards and circled with a thick band of tape. It had been sloppily coloured with a marker pen, presumably as an attempt to conceal it. Somehow, this rendered it more conspicuous. Despite his best efforts, Sam couldn't stop a loud burst of laughter escaping.

Dean woke up with a start. "Hey, Sammy!" he said groggily, "Check it out!" He gestured proudly at the battle-scarred bookcase. "What do you think?"

"Yeah," Sam nodded, grinning widely, "It's pretty great. Bobby's going to love it."

He meant it, too. As far as he was concerned, it was absolutely perfect.