Conn Horgan

When a luminary in the world of medicine is poisoned, Reese and Finch have just 24 hours to determine the deadly toxin he was given and find the person behind the attack. Meanwhile, Detective Fusco’s corrupt past catches up with him when an informant gives the Internal Affairs Bureau the crucial information they need to send him to prison.

Sherlock agrees to take a case from a man claiming to be Moriarty, hoping it will bring him closer to finding his nemesis. Meanwhile, Gregson encourages Joan to give up the dangerous line of work she has chosen and go back to being a sober companion. Natalie Dormer guest stars as Irene Adler.