With These Gloves You Can Pass Through Mirrors

The final episode puts the series' two settled interests side by side. The Inter City Squad investigates rival organisations smuggling stolen art treasures, and the central figure is Peter Mollett, known as the Sandman, an agent handling stolen art and moving it, at least sometimes, inside coffins. A rival gang hopes to cash in on what they take to be a lucrative trade, headed by Gail Merrian with Finbar Malone and Brendon O'Halleran among them. The squad lets the two criminal groups work against each other while the police move in the ground between them, which is the widest the intrigue strand ever gets: two rival gangs, an agent known as the Sandman, a returning Russian and an intelligence liaison.

Running alongside is the event the whole series has been moving toward. Bulman faces retirement, and the episode plays his preparation for the end of his police career against the demands of the investigation, so the closing of the case and the closing of the career happen together. Dugdale returns in the intelligence role, keeping the political and security dimension in play, and Pushkin, played again by George Pravda, appears, carrying the Cold War strand from the Moscow story of Series 4 into the final hour. Claire Lambie is credited, which places the Lambie marriage inside the episode's events rather than in the background, and DS Charlie Baker and DC Harry Collins are among the officers working the case.

The ending is bound up with the gloves that had been Bulman's signature for five years. The title quotes Jean Cocteau, and its image of a pair of gloves through which a man can pass through mirrors is built on the glove motif that defined the character from The XYY Man onward. A pair of gloves through which a man can pass through mirrors is an image of the removal of a disguise, and Bulman's whole method had been disguise, so taking them off is the end of the performance. The retrospective accounts record him walking away from the job and leaving the gloves behind, departing with his ladyfriend in the phrasing of the television listings. The exact ending of the final scene is reported from those retrospective accounts and the glove motif rather than from a frame-by-frame source, and the identification of the person he leaves with is not settled in the sources consulted.

The case is resolved rather than ambiguous, and the man retires. That is a real ending, which no other episode of the run could have: the crime is closed, the lead departs, and the costume comes off. The episode also quietly assembles the show's recurring personnel, Lambie and his wife, Dugdale, Pushkin, Baker and Collins, so that the ending lands on a group rather than a single man. Henderson's last performance in the part is the centre of it, and William Brayne directs. Brayne had also directed the season's second episode and had worked on The Professionals, and he would go on to direct the opening episode of the spin-off Bulman, which makes him the director who closed Strangers and opened its successor.

The finale doubles as a doorway. Don Henderson returned to the part in Bulman, made from 1985, in which the character is a retired ex-officer repairing clocks and working as a private investigator, with Bill Dugdale and Jack Lambie recurring and Derek Willis returning in guest appearances. The honest weakness is that the smuggling plot has to carry a large cast of criminals, intelligence figures and police, and the thread can become congested in the closing hour. What it does get right is the departure of the figure the series was built around, and the title names the gesture with which he leaves.