The second and final season of CBS medical procedural Watson concluded with the episode 'The Cobalt Fissure,' featuring high-stakes medical emergencies and villainous intrigue. Dr. John Watson faces a life-threatening brain tumor surgery, while Sherlock Holmes battles a mysterious condition tied to a past event. The finale leaves some mysteries solved but others dangling amid emotional farewells.
CBS' Watson, cancelled in March, ended its run with an action-packed hour-long finale. Dr. John Watson, battling glioblastoma, sneaks out of Washington Jefferson Memorial Hospital in Pittsburgh to treat his old friend Sherlock Holmes, a patient at UHOP. Holmes, suffering memory loss after going over the falls, recognizes Watson but questions his priorities: 'Is it me you should be looking after, or is it yourself?' Watson's team urges him to prioritize his health, but threats complicate matters. Sebastian Moran, played by Eddie Izzard and a follower of Moriarty, reveals he held Holmes captive and demands his recovery to advance an evil agenda, threatening to kill Mary if Watson alerts police. Moran, a sniper who killed an oncology nurse earlier, heightens the tension. Watson experiences seizures, entering a coma before surgery. Holmes reveals their conditions stem from genetic mutations caused by exposure at the Cobalt Fissure. Shinwell tracks and subdues Moran, handing him to police, though it strains his engagement to Nurse DaCosta. At Watson's bedside, his colleagues and Mary gather. Watson confesses to Mary, 'I was there to say 'I love you,'' envisioning a life together on Baker Street in London. She replies, 'I love that picture,' before kissing him. The episode closes with Watson returning home to Mary on a rainy Baker Street evening: 'You're home early!' Side plots see Ingrid sharing birth mother details with Sasha, returning to therapy, and Sasha pausing her relationship with Stephens.
