Very good direction, acting and dialog are apparent in Sebastian, but a fatal flaw in basic plotting makes this production just a moderately entertaining Cold War comedy-drama.
The amusing, and not so amusing, pressures on persons who break foreign government secret codes are potent angles for a strong film, but, herein, story touches so many bases that it never really finds a definite concept.
Leo Marks’ original screen story, scripted by Gerald Vaughn-Hughes, depicts Dirk Bogarde as a daffy math genius in cryptography. Susannah York, a new recruit to the code force, breaks down his romantic reserve.
Lilli Palmer, as a politically-suspect coder, and John Gielgud, an Intelligence chief, add lustre. Janet Munro scores very well as a boozy fading pop singer who, with Ronald Fraser, attempts to compromise Bogarde’s security clearance.
Despite all the plus elements, film wanders about in its unfolding. Short, tight scenes of good exposition are broken by recurring transitional sequences which add up to an apparent padding effect.