Strangely, he introduces Joan as a doctor that he knows, but Joan manages to play along.
Back at the station, Joan and Gregson have a chat about what transpired the night before.
Thus, shes protective of Gregsons career, worried that being seen with her could ruin his reputation.
Credit: Michael Parmelee/CBS
Sherlock, meanwhile, searches Roslyns apartment and finds quite a few pieces of evidence.
That means someone switched her pills and that the clonazepam could account for the signs of dementia.
So was someone working to cover up Roslyns murder?
He comes into the station and admits that he switched her pills but says he didnt kill her.
So why switch her pills?
That leads him to William Hull, a builder theyd investigated in the past.
So who would have wanted it stopped?
Eventually, things snap into place for Sherlock when a new building plan is put into place.
The solution: make the building smaller, which means Hull wont need to purchase any airspace rights.
The answer: Basquet, the architect and designer.
That is if he didnt get caught for murder, of course.
But, as Joan says, he wont have to do it alone.
Hell have his friends by his side for support.
Perhaps there are romances on the horizon for both Sherlock and Gregson this season.
