‘Are you in the habit of inviting queer men back to your flat, John?’ he murmured, his eyes half-lidded as he stared at John again.

John huffed a breath through his nose. ‘None quite so peculiar as you,’ he said after a long pause, lifting his eyes to Sherlock’s.

October, 1937. A chance encounter late one night leads to Sherlock following John home. I can’t really put it much better than Vera Lynn herself: That certain night, the night we met / there was magic abroad in the air.