Jonny Lee Miller Sherlock Holmes Actor Lucy Liu Joan Watson Actor Aidan Quinn Captain Thomas Gregson Actor Jon Michael Hill Detective Marcus Bell Actor Desmond Harrington Michael Actor Samantha Quan Lin Guest Star James Urbaniak Dr. Leo Demopoulos Guest Star Maulik Pancholy Alfonse Templeton Guest Star Douglas Hodge Sydney Place Guest Star Reg E. Cathey Mr. Clay Guest Star John Hillner Milt Reed Guest Star Robert Doherty Executive Producer Carl Beverly Executive Producer Sarah Timberman Executive Producer John Polson Executive Producer Jason Tracey Executive Producer Liz Friedman Writer Guy Ferland Director