He's boldly going back. 

On Monday, Patrick Stewart tweeted a photo as work began on his return to the Star Trek universe, where he'll once again play Captain Jean-Luc Picard in a new untitled series for CBS All Access. (Disclosure: CBS is the parent company of CNET.) CBS All Access is the network's digital subscription video-on-demand and live streaming service.

"The journey has begun," Stewart tweeted.

The photo doesn't give away any spoilers. Stewart is casually dressed in what looks like jeans, a white T-shirt and sweater, and holds his glasses in one hand. He's sitting around a table with show staffers, including Pulitzer Prize-winning author Michael Chabon, one of the show's executive producers.

Last week, Chabon posted a photo of The Klingon Dictionary and the Star Trek Spaceflight Chronology to Instagram, writing, "NOTE: as with previous posts, contents of this photo do not indicate, suggest, or in any way hint at plot, setting, timeline, or featured characters of #untitledpicardproject. @trekmovie, I'm looking at you. They do, however, suggest a man in the grip of a profound, joyful and helpless re-obsession with the #sacredmaterials."

Little has been revealed about the new show, except it's said to "follow the next chapter of Picard's life." There's no official title or date yet, but it seems likely to premiere in 2019.