The actor/stand-up was a breath of fresh air during the heaviest moments of the season.

[Editor’s note: The following contains mild spoilers for “Star Trek: Discovery” Season 2 Episode 14, “Such Sweet Sorry, Part 2.”]

“Star Trek” has a history of bringing in unexpected stars, all drawn to the franchise by their passion for the source material. And with the latest iteration, “Star Trek: Discovery,” that tradition has continued in a number of respects, but none more interesting than the casting of Tig Notaro as engineer Jett Reno, introduced in the first episode of Season 2 and who proved to be a delightful presence over the course of the following episodes.

Notaro is best known as a stand-up comic whose riffs on her cancer battle and pop culture ephemera eventually led to the critically-acclaimed Amazon series “One Mississippi,” which ran for two seasons before its unfortunate cancelation. Her low-key but raw and honest work in “One Mississippi” was not one that might obviously lead to an appearance on the newest edition of the sci-fi icon, but she happened to have a decades-old relationship with “Discovery” showrunner Alex Kurtzman, who created the character of Jett specifically for her. “He knows my voice really well,” Notaro told IndieWire in 2018. “My character, I’m telling you, the writing that was done for my character is just spectacular.”

What’s fascinating is that while Notaro’s work on “Discovery” might feel somewhat unconventional, it actually invokes one of the great classic “Star Trek” characters — Dr. Leonard McCoy, first played by DeForest Kelley and later emulated by Karl Urban. While Jett Reno is officially an engineer, she uses her technical expertise to keep her marooned crewmates alive after the crash of her original ship, the Hiawatha. More importantly, she brings that same irreverent energy, that refusal to deny basic facts, that made McCoy so iconic to the original series. While the language is a bit more modern for the era, it’s not hard to imagine Kelley growling “get off my ass” while in the middle of a high-stakes situation.

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But at the same time, Notaro has brought her own unique low-key energy to the often high-stakes intensity of “Discovery,” calmly refusing to circumvent the laws of time and space despite the demands of her superior officers. In a series largely lacking levity, she has proven to be a reliable source of humorous asides even in the most chaotic of circumstances — something special to treasure, especially as the show launches forward into a very uncertain future (literally, thanks to the events of the Season 2 finale). She has yet to find her own version of McCoy’s running joke (“he’s a medical doctor, not a [FILL IN THE BLANK]”), but she honestly doesn’t need one.

It’s also important to note that after decades of “Star Trek” only finding cursory ways to acknowledge its LGBTQ fanbase, Notaro’s character was established as a widow whose wife had been killed during the Klingon war — a relationship accepted, much like the bond between crew members Stamets (Anthony Rapp) and Culber (Wilson Cruz), as something natural in the 23rd century. (As it should be.) Progress for representing same-sex relationships in the future of the Federation has been slow, but Jett stands out as the first openly lesbian character in a “Trek” series.

In the long run, the promise of “Discovery” from the beginning has always been the opportunity to introduce characters like these — folks who fit slightly out of the mold, but still represent the message of “Star Trek.” Because of the choices made at the end of Season 2, Notaro is poised to continue her voyage with “Discovery” into Season 3, and that’s thrilling news.

“Star Trek: Discovery” is streaming now on CBS All Access in the United States, and Netflix internationally.

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