Michael Biehn wears a Seiko S234 Pulsemeter

The most famous prop in Aliens is a gun that does not exist and also does, the M41A pulse rifle the Colonial Marines carry into the dark on LV-426. Look under the plastic shell and you find a Thompson submachine gun, fitted with the pump-action of a Remington 870 shotgun and a heat shield off a SPAS-12. James Cameron's future was built this way on purpose. Take a real object, change its skin, and let the audience's eye do the rest.

The watch on Corporal Hicks's wrist is the same trick, smaller.

It is a Seiko pulsemeter, an ordinary digital watch sold in the mid-1980s to runners who wanted to check their heart rate. It came with a chest strap and a touch sensor that did the measuring, and the watch only displayed the number. For the film, the props department went over each one and painted out the Seiko name, then blacked over the bright yellow buttons so nothing would read as a consumer product. The work was not quite perfect. In a few shots, collectors have noticed, the black paint has worn through on a button to show the yellow underneath.

Here is the part the usual telling of this watch gets wrong. It was not Hicks's watch. It was everyone's. Hudson wore one, and so did the rest of the squad, because that is what a unit is: identical kit issued to everyone, no exception for the corporal who happens to keep his head. Michael Biehn plays Hicks as the calm one, the marine who takes over when the officers fail and who hands Ripley a tracking bracelet before the end. None of that is on his wrist. It is in how he behaves.

What the watch tells you is something about the movie, not the man. Aliens is set in 2179, almost two centuries from now, and the gear Cameron chose to send that far forward was a fitness watch you could have bought at a mall in 1986. Some technology, the choice quietly argues, arrives early and then simply stays. The Marines fight xenomorphs with a heart-rate monitor and a tarted-up tommy gun, and neither one looks out of place.