Years after the Battle of Hogwarts, George found Fred sitting in his kitchen. Fred. In his kitchen. After the Battle.
Completely baffled, George stumbled off the top step of the winding staircase of the Burrow and came to a standstill in front of his brother. His brother, for god's sake… He… was supposed to be… he wasn't alive any more. George couldn't bring himself to think of that word. But there Fred was, chipper as ever, seated in his favourite armchair in the corner. "Mornin'!" smiled the ghost of Fred, legs draped over the soft worn red leather of the arms. George continued to gape. "What- h-how… you're… no, you can't be… how…" His tongue kept tripping over itself, but Fred helped by pushing him down into the armchair. "The old girl upstairs let me come down just for one day, so I could see you."
The pair spent the next few hours true to traditional Weasley twin style, joking, chasing the gnomes in the garden, and laughing loudly all the while. George shared everything that had happened to him, and showed Fred all that he had done with the shop. The two of them hooted for a good hour, over recalling all their pranks during their time at Hogwarts. It was wonderful but saddening all the while, as neither of them could release the heavy burden that was the knowledge that Fred was but a ghost.
The day drew to a close, as days tend to do, and as the sun slipped below the horizon, they both knew it was time. They were back in the house, Fred nestled in his armchair, George perched on a stool in front of him. George couldn't even embrace his brother, his twin, the other half of his life, but Fred's next gesture was enough. Wordlessly, he reached out and touched George's heart. "If you ever need me, I'll always be here," he said, and turned and disappeared.
A single lonely tear rolled down George's cheek, but he was the happiest he'd been in a long time.