"Shall we undress?"
Joan gives Sherlock an unimpressed stare as she looks up from her papers, but she can't hold her expression once she notices Marcus' horrified look at both of them.
"He means undress the wall," Joan explains, gesturing to where all their leads and clues had been put up as a better way to examine them while they sort through information in the Brownstone. Sherlock likes to rearrange whenever they get stuck and need a new perspective.
"Good," Marcus replies with relief as he sets down the stack of files in his hands. "Because I was about to regret agreeing to help sort through this stuff if things started getting kinky around here."
Sherlock starts pulling thumb tacks out of the wall. "Oh things get kinky around here, but it's usually after 3am and involves a copious amount of rope."
Marcus grimaces and then runs his hands across his face as if he's trying to manually wipe away whatever mental image he'd just conjured up.
"Perhaps we should get back to the case," Joan says, bringing them back on topic before Marcus decides never to speak to them ever again.
"Good," Sherlock says, taking a step back to examine the wall again. "Because I think I have a new theory, and it involves goats."