Luke Skywalker might wear a kyber crystal necklace in Star Wars: Episode VIII — The Last Jedi housing the power source of his father’s red lightsaber.

On Monday, a rumor was published by Jason Ward at Making Star Wars who says he has it on good authority that Luke has a kyber crystal that he’s “protecting and/or hiding” and that he’ll be wearing a strange necklace under those robes with “a red crystal protruding from the bottom of it.”

The aging Jedi apparently takes his fashion tips from Rebel Jyn Erso, who famously wore a white kyber crystal given to her by her mother in Rogue One. It almost even seemed like Jyn used the Force at one point while concentrating over her crystal.

While perhaps most famous for being the Force-attuned power source at the heart of each and every lightsaber, kyber crystals were also harvested from Jedha to power the Death Star. If Luke does wear a red one around his neck, it’s almost certainly the one that once powered Darth Vader’s red lightsaber.

Luke looks on at the funeral pyre for his father.

In their duel on the second Death Star, Luke severs the hand clutching the red lightsaber, but we don’t get a clear picture of where it falls. It’s possible that Luke kept the saber after all these years and that it will play a role in the upcoming Star Wars: The Last Jedi. The biggest secret of all would be how he got the saber off the second Death Star to begin with.

We’ll know more when Star Wars: Episode VIII — The Last Jedi hits theaters on December 15, 2017.