The Security Guard Theory
Is Luke Skywalker in a secret location, guarding a Sith tomb? This theory speculates that the tomb contains a powerful evil which Kylo Ren and his Knights wish to unleash among the stars. It also speculates that the reason for Luke’s lengthy shift is that the tomb can only be opened by his old lightsaber – or perhaps even his lost hand – last seen tumbling into the void in Star Wars: The Empire Strikes Back. There follows a race against time, in which our heroes, old and new, must try to reach Luke ahead of the forces of darkness.
Certain shots from the trailers could arguably support this theory – Luke’s mechanical hand on R2-D2, the melted helmet of Darth Vader atop some kind of shrine, Han and Chewie in the Millennium Falcon, Finn and Kylo Ren battling in the forest, Kylo Ren putting the psychic whammy on Poe Dameron (Oscar Isaac) and envisioning laying waste to a forest, Han comforting a concerned Leia in an ‘I’ll get your loved one back’ kind of fashion – all these snippets could be interpreted as being part of a ‘Race To The Jedi’ situation.
I would humbly suggest that this is the least likely of all the theories, however. While it does contain a call-back to an event in the original trilogy – the loss of Luke’s hand – it features no other threads that are really in keeping with the Star Wars universe of Luke Skywalker. The existence of a Sith tomb seems almost too random and, frankly, has more in keeping with the plot of Indiana Jones And The Last Crusade.