The plot of the season premiere is simple: The Discovery links up with a disabled Enterprise — and what a joy to see the classic ship depicted with 21st century graphics — and must investigate several “red signals” that are emerging across the universe. Pike takes control of the Discovery, with Mount evincing the same rugged charisma Bruce Greenwood brought as Pike to the J.J. Abrams “Star Trek” films. I should also note: Mount also serves as an indirect replacement for last season’s rugged captain, Gabriel Lorca (Jason Isaacs).

“Brother” has everything that the best episodes of “Trek” have historically had: a mystery, excellent ensemble work with a genuine sense of camaraderie, action scenes that don’t overwhelm the plot and most importantly, genuine fun. Several episodes in the first season of “Discovery” didn’t work because it didn’t feel like the crew enjoyed being around each other — recall for example how much antipathy members of the bridge had toward Burnham for much of the season.

Now, that seems to have melted away. In addition, Tig Notaro — TIG NOTARO! — is a welcome addition of the cast as Jett Reno, an officer who has found a way to keep her crash-landed crew alive even though she’s not a doctor. It’s great fun to watch one of the world’s best stand-up comics navigate the “Star Trek” universe — and Notaro really seems to embrace her role with gusto.

Another aspect from last season which thankfully we don’t see in the premiere: Klingons. The depiction of the Federation’s most hated foe was very poorly received by fans, for good reason. The dialogue was difficult to follow and the choices made by the characters were baffling. Now, it appears that Klingons and the Federation are at peace — and we don’t have to see them for a little while.

But there is an elephant on the bridge. Spock, who will be played by Ethan Peck, was not seen in the season opener. This is the one element that has left fans on edge since even before the series premiere. It’s always been a sore point that Burnham is supposed to be Spock’s foster brother, whom apparently we never hear about in the history of all of “Star Trek.” In “Brother,” we get hints about this. Burnham suggests that Spock didn’t accept her as a sibling — which seems, frankly, out of character for Spock, but it’s too early to determine that until we see how this story unfolds.