The Star Wars franchise isn't just about movies. Its attendant novels, comics, and games have always been important too — especially since 2014, when all new publications became part of official Star Wars canon. These days, all tales from the galaxy far, far away tie into each other in subtle ways under the guidance of the Lucasfilm Story Group.

And that's why you should be paying attention to Darth Vader, a new comics series by Marvel. In Darth Vader #2, published this week, we're introduced to an old Jedi vow that may well explain why Luke Skywalker went missing before The Force Awakens — and steal some thunder from Luke's tale in this year's The Last Jedi.

The background: Vader has been tasked by Emperor Palpatine with building a Sith lightsaber. He has to do this by finding and fighting a Jedi, which is the only way he can take the all-important lightsaber-powering kyber crystal (which we learned about in Rogue One, remember?) and turn it into an evil kyber crystal.

Trouble is, nearly all the Jedi were just killed in the Order 66 massacre. So Vader does a bit of galactic googling to find any spare Jedi who had hidden themselves after taking the "Barash vow." Here's the page where it plays out:

Image: marvel

"Complete disengagement from anything but the Force" certainly sounds like a guy who hid himself on a faraway island planet, then removed said planet from all the maps — which is what Luke did prior to The Force Awakens.

A type of penance? Well, Luke certainly seems pretty haunted, and with good reason. It's entirely possible that his training of Kylo Ren helped lead to the massacre of his newly rebuilt Jedi order and the rise of the First Order, which has already resulted in the deaths of millions.

And Jedi Barash takers would not allow themselves to respond, even to a galaxy-wide massacre of Jedi. Well, that explains why Luke wouldn't have lifted a finger against the resurgent First Order or Supreme Leader Snoke.

It also gives credence to the common fan theory that Luke and Rey are related in some way. If he dumped young Rey on Jakku all those years ago, he's an asshole; if he left her there because he took an ancient vow, he's still kind of an asshole, but at least he has a good excuse.

And just in case you're wondering — no, we've never heard of the Barash vow before now, not even in the novels and comics that are no longer canon.

You may consider this mere speculation over what may turn out to be an unrelated comic book plot point. But these days, there's very little that's unrelated to the wider Star Wars story, even in the comics.

For example, earlier in the same issue of Darth Vader, we see a bunch of clone troopers talking about how their cloning facility has been shut down. This nugget of dialogue seems laser-targeted at the persistent half-baked fan myth that clone troopers and stormtroopers are the same thing:

Image: marvel

Darth Vader #2 is on sale now in all good comics stores and apps. Luke Skywalker's story in The Last Jedi, with or without the Barash vow, hits theaters on December 18, 2017.