Leonardo DiCaprio wears a TAG Heuer Carrera

Leonardo DiCaprio's Dom Cobb sits in a room walled to the ceiling with small glass bottles, an apothecary's stock, while Ken Watanabe's Saito stands behind him. On Cobb's left wrist is a steel watch on a steel bracelet, the kind of thing you can pick out in the frame but not quite read. It is a TAG Heuer Carrera Calibre 5, reference WV211B.BA0787, the plainest watch the brand makes: thirty-nine millimeters, a black dial, a date window at three, an automatic movement and nothing more. There is no chronograph and no dive bezel, which for the film's lead leaves him in the most modest TAG in the catalogue.

The Carrera carries more history than that modesty lets on. Jack Heuer introduced it in 1963 and named it after the Carrera Panamericana, a Mexican road race so lethal it ran for only five years, from 1950 to 1954, before it was abandoned. He had heard about the race a year earlier from the parents of two racing brothers, and he built a chronograph meant to be read at speed, with sharp faceted lugs and pushers a driver could work while wearing gloves. The watch on Cobb's wrist is the quiet descendant of that one, the same name carried over with none of the urgency.

There is no mystery to why it is a TAG. DiCaprio was a TAG Heuer ambassador when Inception was shot, which is reason enough for the brand to land on the lead's wrist, so the watch on screen reflects a real endorsement rather than a prop department's pick.

The film runs on time. Five real minutes can stretch to an hour one dream-layer down, and the distortion compounds the deeper the team goes, which is how Cobb and his dead wife Mal end up lost for what feels like fifty years at the bottom. But the object Cobb trusts to tell a dream from waking life is not the Carrera but a small spinning top, and the watch is just what he happens to wear.