Spoiler alert: This review contains significant details from Sunday’s premiere of Star Trek: Discovery.

In the optimistic spirit of Star Trek, the newest series in the legendary franchise offers hope for its future, but expect some turbulence along the way.

Star Trek: Discovery, the CBS All Access sci-fi series (**½ of four stars) that premiered Sunday with two episodes (the first on CBS), soars in ambition and devotion to Star Trek history and mythology, but stalls with certain plot details and stilted dialogue.

Next week’s third episode, which sets the series on its true course, features more promising plot twists and character possibilities, something to consider when deciding whether to pay for the streaming service. (After a brief free trial for new subscribers, the monthly fee is $5.99 with “reduced commercial interruptions” and $9.99 without commercials.)

Discovery, set 10 years before the events of NBC’s original 1960s TV series, centers on Michael Burnham (Sonequa Martin-Green), first officer of the United Federation of Planets’ USS Shenzhou serving under Captain Philippa Georgiou (Michelle Yeoh).

Burnham’s background offers rich story potential:  The brilliant human girl was raised on Vulcan by Mr. Spock’s parents, Vulcan ambassador Sarek (James Frain) and his human wife, Amanda.

Sunday’s episodes followed the Shenzhou to a remote corner of the galaxy, where the brave Burnham’s deadly encounter with a Klingon triggers a war.

Too many actions worked against character or logic, perhaps the result of bumps in development that delayed the premiere and led to the departure of executive producer Bryan Fuller

Early on, Georgiou won’t tell her second-in-command why they’re walking in an odd pattern on a desert planet, seemingly to surprise viewers with the revelation they’ve traced the Star Trek insignia so the Shenzhou can find them. Later, the pair proceed on a likely suicide mission against the Klingons, a move that seems only to steer the plot forward. That’s what redshirts are for!