John and Sherlock duck gingerly into the cab, shaking off the rain once inside. The windows are already beginning to steam over as Sherlock leans forward, giving the driver the address. Beside him, John runs a hand through his wet hair.
"Sherlock?"
"Hnn."
"Are you... wearing perfume?"
Sherlock turns slowly and pins John with a very unamused look.
"Really, John, you can be so disappointing. At times you demonstrate that your powers of observation have increased tenfold, and yet this is only half the work. If you do not couple keen observation with sound, logical reasoning then your conclusions will become... ridiculous." He continues to glare at John for a beat, before turning to look out the window.
"It was just a question! Jesus. It's not like you haven't dressed in drag before. Or what about that week you were trying on every kind of lipstick. That was-"
"Those were obviously experiments, John," Sherlock is glaring at him again. "I have no such time for erroneous tests as we are on a case."
"Well, all I'm saying is it's not that illogical to think you'd wear perfume," John feels justified.
There is a moment where Sherlock glowers and John privately thinks that Sherlock can be a massive git, before Sherlock's expression smooths out.
"It is, in fact, Mrs. Hudson's new perfume, which would have been obvious to you, had you cared to pay attention to the state of the landing this morning."
"Sorry...the landing?"
"Yes," Sherlock leans forward, beginning to look animated. "Obviously the landing had been cleaned in the past 24 hours yet no bleach had been used, as is Mrs. Hudson's preference. Instead, a cleaning solution with a pungent floral aroma had been used in it's place. One can conclude from this fact that Mrs. Hudson was concerned with the smell lingering.
"Why? Because the smell of sodium hypochlorite concentrated bleach is notoriously difficult to rinse from one's skin. Furthermore, the door to 221a was locked when we left just now, even though it is four in the afternoon. We know her Bridge games meet on every other Thursdays and that she goes shopping on the weekends, so we can deduce that it was a personal engagement.
"Conclusion? Mrs. Hudson has a date and has purchased a new perfume for the occasion."
"But then why are you wearing it?" John looked entranced through the monologue.
"Really John," Sherlock sighed. "Pay attention. What can you tell from the state of my coat?"
John's eyes drifted downwards, taking in the Belstaff coat's lapels. Sherlock didn't give John time to look before he launched into an answer.
"The make-up, John! Smudged just here, leaving a faint imprint where Mrs. Hudson embraced me earlier in the evening, inadvertently transferring some of her make-up – and perfume – on me in the process."
There was a beat of silence between them as the rain pummeled the windows of the cab.
"Brilliant."
Sherlock couldn't have looked more like a cat purring if he had tried. He leaned back and turned to look out the window once more.
"Although," John began. "I do hope this new make-over of hers is for someone decent this time."
Sherlock snorted. "Really John, I never took you for the naive type."
Beside him, John sighed.