I personally thought that was an incredibly mediocre episode. Nothing actively awful, just...there.
I'll start with what I liked: That the frame of reference for the episode was away from Michael, and placed firmly on Book and his trauma. It was appropriate given his entire homeworld was unceremoniously fridged last week. It would have been nice if he at least referenced in passing not just the death of his nephew, but his entire species (I think - it's one of those weirdly unpopulated Trek planets) but this is a small issue with the centering on grief. Book got a coherent character arc from start to finish, and I can't ask for much more in an episode of Trek.
The downside was...basically everything else? The entire first half of the episode was an example of why you should show, not tell, with almost all of the run time given over to expository dialogue. I know this is a very old trope in Trek (TOS episodes had dialogue so expository you could follow the action just by hearing the bridge narration) but it didn't make for effective drama - at least for me. The scene at Starfleet HQ in particular felt like sitting through a powerpoint presentation, with the writer explaining what was happening to me via interchangeable cast surrogates. The other side of this episode was some of the character beats, but (IMHO) everything is just a bit too loving and supportive - as if everyone is just so afraid not to be the perfect listener. This is part of why the interaction between Stamets and Book stands out so well - Stamets may be trying to do the right thing, but he's not always succeeding, and he's working through his own shit as well.
Regardless, this would have been a much, much better episode if it was told almost entirely from the frame of reference of Book and Stamets. Every time the story lost this focus, my interest waned.
