Jim Moriarty kept what most ordinary people would call an observation diary (or at least, that was the name he assumed people would ascribe to his musings).
In his diary, he stored information about his petit lapin. Not information that was easily accessible for Jim, like her birth certificate, or where she lived, or her place of employment. Important material, like where she ate at 2pm on a Saturday afternoon, or what dress she was wearing to a party, or a detailed description of the man she sat next to on the tube.
But Jim wasn't ordinary, not in the slightest, and so his observation diary was in reality not a diary at all. He stowed away every sighting of his petit lapin entirely in his memory, from the first day that he ever laid his eyes on her in the library to the day she initiated their first conversation.
It was his very own mind palace and it belonged entirely to him. Jim was the man with the key.
On November 28th, Jim was sat in an armchair, legs crossed idly over the mahogany table finish in front of him, when she drifted into the library. Her eyes perused the room absent-mindedly as she wandered, pausing in discreet admiration at the high ceiling with the gold blue pattern. She'd been here before, blatant from the way she glided over to the bookshelf opposite Jim with familiarity, but she was nevertheless awe struck by the magnificence of the room itself. Jim had seen it before in humans – a tendency to be amazed by the same dull thing time and time again. Jim watched intently as his petit lapin traced her slender finger across the row of books, his own digits gently stroking the armchair's fabric in accidental synchronisation. Her finger lingered when she reached a deep red hardback – Jim's lingered, too. She removed it from the shelf with the precision of a surgeon, sliding it effortlessly from the other books. She left then, her fair, silky ponytail streaming down her back, and Jim did not see her again for exactly two months.
Jim's petit lapin looked at him on 2nd April. It was 3:21pm when Jim stepped onto the Bakerloo line train, two stations prior to its final destination. She was already seated, pointed chin resting on her chest, dark blue fountain pen poised above a notebook on her lap. Jim sat opposite her as the train pulled away, dark shadows shrieking past the windows. He watched her raise the pen to her mouth as the carriage jolted and run its blunt end gently across her pale pink lips. When the train stuttered to a halt at Lambert North, her eyes fleetingly met Jim's.
Jim made a reservation at the same restaurant she was eating at with her partner on 5th May.
"She looks like a little bunny rabbit, doesn't she? All helpless and nervous and shy," Jim told Sebastian.
Sebastian turned his head and glanced at the girl again. "It's because she knows you're staring at her," he replied flatly, opening the bottle of red wine that stood between himself and Jim.
"She could almost rival Sherlock Holmes," Jim muttered. "My petit lapin."