Watch All Night (1980)

Seventeen-year-old Tess Eveling (Lucinda Bateson) meets her father, Dr Gerald Buscombe (Paul Ratcliffe) in London for a short sight-seeing holiday. Tess's father - a nuclear scientist who works for the Middle Eastern state of Y-Bana - disappears from Room 13 of the Columbia Hotel in the middle of the night, and by morning there is no trace he was ever there. In fact, even his hotel room has vanished. A wall of silence faces distraught Tess so she seeks help from Max (Robert Longden), a friendly librarian she met on the train to London, as she struggles to convince those around her of her father's disappearance.