Elementary - Season 4, Episode 12: Soundtracks

Joan meets with Fiona at a cafe who request that Joan look into her new boss because she suspects he may be a criminal like her previous boss, Joan willingly offers her services to her.  

Joan reports back to Fiona on her boss Greg Wakino with her remarks on him then Fiona gives her a book to return to Sherlock that he had previously lent to her during their last encounter. 

Sherlock stops by Fiona house, Fiona lays her cards on the table as a neural atypical and what it would be like to date her which Sherlock doesn't shy away from her then asks her out for coffee.