The cab ride to the Morstan residence was bumpy, cold, and treacherous, but once the cab finally pulled over (a block away, just in case), Sherlock felt himself heat up with excitement—the sort of tense, shaky excitement that was tied closely to fear (epinephrine, C9H13NO3) that he rarely felt.
But tonight he was taking a risk. Tonight was only the second time he had returned to London after the fall.
It had been a year, and Molly had told him that John was engaged to Mary Elizabeth Morstan, the sister-in-law of the CEO of a major weapon manufacturer. Sherlock had been unable to find out much else about her. He couldn't even find her father's name. He did know that her mother passed while she was very young (Elizabeth Anne Morstan—cause of death unspecified) and that John was very much enthralled with her.
And so Sherlock found himself scaling a large fence to the side of the yard (it was just dark enough that he wouldn't be noticed), silently scaling a large pine tree near a window that led to the dining room, slipping binoculars out of his bag, and watching.
John and Mary were sat at a table inside, much larger than necessary for two people (the house was something of a mansion, after all), eating in silence (home-made food. Mary's cooking?). Sherlock turned his attention to the woman.
Her hair was dark, pulled back into a loose bun. Green eyes. Something about her made Sherlock feel queasy—it could have been the makeup that made her look plastic-y and a bit too good to be true. Her face looked bizarrely familiar. She wore a little black dress, fitted tightly around her curves but not so much as to appear uncomfortable. Her fingernails were painted to match her lips, all smooth and precise and perfect.
Sherlock then focused his attention to John. He had bags underneath his eyes, more prominent than when he was with Sherlock. His hair looked very military, as did his posture,but he hadn't returned to the war, no... This was something else. His cane was propped against the table where he'd set it down—limp returned. That much was easy enough. His shirt was ironed, most likely not his doing. Mary's then. He was living with her (221B remained empty, although Molly had said something about 221C being rented) and had a new job, seemed happy but... off. Something was off.
Sherlock watched as the couple finished their meal, chatted for a bit, and Mary retreated into the living-room. Sherlock made his way down from the tree and found some hedges near a window which was, luckily for him, open. He crouched in them, listening intently for signs of movement.
The sound of a mobile phone being flipped open. Click. A pause.
“Hello, Sebby. … Yes. … Yes, he was taken care of. How is the Wellington case coming along? … Good.” Sherlock's mind raced. Sebby? Seb. Sebastian. Sebastian who? And Wellington... Where had he heard that name before?
“Tomorrow, at... three? Good.” Another click. Some pacing, then footsteps leaving the room.
Sherlock sat there for what seemed like hours (but, in reality, was only about fifteen minutes), thinking over his next move.