Daniel was packing his things away the morning after the bonfire. Most of the school supplies had been put away already, but most of his clothing was still in the closet. He started putting them away in the order of least to most likely to be needed over the summer, and as he reached near the end of that spectrum, he noticed he must have put away his favorite blue shirt too soon.
So he unpacked his clothing again, watching for the blue shirt so he could lay it aside for later, and was surprised when he reached the last of the green robe uniforms and it hadn't yet appeared. Frowning some more, he began to look inside his clothes in case it had gotten caught inside another shirt or robe, but even that search did not reveal the blue shirt.
Packing away all of the clothes for the second time, he kept a close eye out for it but it remained missing. Once all his clothing was in his trunk, he closed that and performed a close search through the closet, in case it had gotten caught up in a pocket of weak space-time caused by his expansion charm but, despite finding a sock that had been missing since fourth year, no blue shirts were discovered.
Then he looked under his bed, under his mattress, between his sheets, and inside his pillowcase, but it wasn't in any of those places either. Neither was it in the bathroom anywhere - not under the sink, not on the towel racks, not in the shower. Daniel returned to his closet and frowned into it, confused. He'd had it yesterday. He was sure of that, because he'd worn it two days ago, and the House Elves had returned it freshly laundered, and he'd put it away.
He gave the closet, his bed, the bathroom, and his trunk another look through, and this time he took everything out of his trunk to make sure it wasn't there. It wasn't.
By then, he was starting to attract the attention of his roommates with his increasingly distraught movements, and he looked over to them, hoping they might have packed it by mistake somehow. "Have any of you seen my blue shirt? The one with the buttons?" His finger drew a line down the front of his chest to demonstrate where the buttons were. "I can't find it."