Despite his grim discovery, Tulkinghorn remains undeterred from his ruthless inquiry into Lady Dedlock's past. A young crossing sweeper, Jo, may hold a key to the mystery. Krook discovers evidence in Nemo's room which could provide a crucial clue. Richard and Ada plan their engagement, but receive an unexpected setback. And as Richard begins a career in medicine, Esther meets an attractive young doctor called Allan Woodcourt.