1x3: Vigil

: Kirsten discovers that the murdered activist Jade was the illegitimate daughter of MSP Patrick Cruden , a prominent anti-Trident politician.

: MI5 agents begin openly trailing Kirsten Longacre on land, signaling that the investigation has moved beyond a simple murder case into a matter of national security. Vigil 1x3

: DCI Amy Silva confirms that Craig Burke did not die of a head injury but was poisoned . She discovers a strange substance on his lips that matches residue found on his clothing. : Kirsten discovers that the murdered activist Jade

: Files on Burke’s stolen USB stick reveal an illicit affair between the sub’s medical officer, Lt. Tiffany Docherty , and the coxswain, Elliot Glover . Burke had been using photos of the two to blackmail or "shitlist" the crew. Character Revelations She discovers a strange substance on his lips

: Much to her dismay, Captain Newsome informs Silva that her stay on the submarine has been extended from three days to three weeks . Vigil Episode 3 Review: For Bros In Peril On the Sea!

The third episode of the first season of the BBC drama (1x3) serves as a pivotal turning point, shifting from the immediate high-octane tension of the initial episodes into a complex investigative phase that reveals deep-seated naval and political conspiracies. Core Plot Developments