"Why did you leave Starfleet, Admiral?"

That chilling question lingers over the first teaser trailer for "Star Trek: Picard," the upcoming CBS All-Access series that brings back Patrick Stewart as the venerated leader who once captained the Enterprise on "Star Trek: The Next Generation."

The teaser is comprised of sun-dappled footage from Picard's winery, where he has retired after his space-exploring career. But in voiceover, a woman wonders what an "unimaginable" tragedy cost Picard. "Your faith in us? Your faith in yourself?"

Showrunner Alex Kurtzman has described the series as a contemplative character study. "What happens when circumstances have conspired to not give him the happiest of endings?" he told the L.A. Times. "Hopefully, it’s a reinforcement of ["Star Trek" creator Gene] Roddenberry’s vision of optimism. He’s going to have to go through deep valleys to get back to the light."

"Star Trek: Picard" does not yet have a premiere date.