
One of the best things about the Apple TV+ adaptation of Murderbot is the various ways that the series is expanding the original Martha Wells books. This is happening not just on a character level, but also in terms of expanding the timeline. Not only have we glimpsed flashbacks to the creation of SecUnit, but now, in Episode 7 of Murderbot, “Complementary Species,” one flashback changes the entire nature of the PreservationAux team, and adds a slight departure from the source material that enriches one of the most interesting characters.
Spoilers ahead.
At the start of Episode 7, we get a flashback to the moment before the PreservationAux has departed, and it's here that we learn that augmented human Gurathin (David Dastmalchian) was once a spy for the Corporation and that he had, at one point, intended to betray Mensah (Noma Dumezweni). But, because he was wracked with guilt, and very clearly is in love with Mensah, he changed sides, and has been with PreservationAux ever since. Plus, Mensah forgiving Gurathin for nearly betraying her also just made his unrequited love for her even stronger.

The idea that Gurathin has deep feelings for Mensah is a fairly new development for the TV series, as is the idea that he is a former spy. By revealing the latter, the series has created a reason why Gurathin distrusts SecUnit so much. It’s not just a matter of recognizing that SecUnit has a technological advantage over the humans (so does Gurathin), it’s that Gurathin himself was once a Corporate Spy, so he’s in a unique position to spot one. This idea isn’t directly from the original books, and the word “spy” doesn’t appear in the first novella, All Systems Red, at all.
On top of this, Gurathin’s deep feelings for Mensah, revealed in this episode, also change the nature of this already complex character. The idea that the PreservationAux team performs a “sweet/bitter” ritual in which they reveal good and bad things about themselves and each other is also unique to the TV series and not found in All Systems Red. This makes a certain amount of sense because while most of the action in the books is from the point of view of SecUnit, the new flashback in Episode 7 happens before SecUnit even meets the team. And, by revealing that Gurathin is in love with Mensah, Murderbot has turned a grumpy, untrustworthy character into a sympathetic one.

“To me, it's incredibly profound,” David Dastmalchian tells Inverse. “This revelation, and the history of how this actually started, that’s the reason she [Mensah] means so much to Gurathin.”
Like many fans of the books, Dastmalchian was fully aware that this was a change from the source material, but he also made clear that he and actress Noma Dumezweni felt that the story of the show “follows the breadcrumbs” laid out by writer Martha Wells.
“I’d say it's very obvious from Episode 1 that Gurathin is deeply in love with Mensah,” Dastmalchian explains, “She's alluring. She's a strong leader. She's the problem solver. She has the power of the group. So why wouldn’t I be in love with her? Well, now you know there’s something even deeper.”