But while he's playing coy on his appearance in Episode VII, it seems Luke may well already be filming scenes for Episode VIII. Mark Hamill, who played Luke in the original trilogy, appeared to indicate he was reprising the role in the as-yet-unnamed Episode VIII in a tweet posted this weekend, in which he described his shaving regimen. Director J.J. Abrams apparently wanted a more hirsute take on Luke for the upcoming Star Wars trilogy, which is set 30-plus years after the battle of Endor. Hamill first described his "contractually obligated beard" in August last year, showing off his bushy facial hair in a shot from the Episode VII set, but has trimmed it back and removed it entirely for appearances in other TV shows since.

Luke Skywalker has been conspicuous in his absence from Episode VII's promotional materials, but we might have actually seen him in one of the earliest trailers for the movie. One of the shots in the first Force Awakens trailer, released in April this year shows a character, his face turned from the camera, sporting a robot hand and stroking R2-D2 on what appears to be a volcanic world. That certainly fits Luke's profile — missing hand, fond of capes, big fan of stroking astromech droids.

Extrapolating on that short scene for a minute, we can build up a potential picture of Episode VII's plot. Luke has journeyed to Mustafar, the place his dad got his own hand (and arm, and legs) cut off, to find something. Perhaps he's looking to understand the Jedi — his downgrade in hand quality indicates he's living a monk-like ascetic life — or perhaps as some think, he has started down Anakin's path and gone full evil. Either way, Luke is off the grid, as he was when he went to do handstands on Dagobah with Yoda. Han, with Finn and Rey in tow, are trying to find him, either to bring him back into the fold as the hero of the Rebellion — re-branded as the Resistance — or to turn him from his dark path.

As for Episode VIII, anything goes. Luke could fall under the sway of a new Emperor, or fall in love with a computer, or join a cult led by a trans-dimensional gelatinous blob. Or he could simply be re-appearing as a Force spirit, a neat trick Star Wars can pull out of its back pocket whenever it wants to resurrect a character to stand around at parties like a literal ghost at a feast. If he is back as a spirit, expect him to be scrubbed and replaced by a similarly aged Hayden Christensen in another 25 years.