I'm not that far in, and a few thoughts have flashed as I've read (and tried to keep myself awake):

1. The book has an acknowledgement thanking Douglas Adams for inspiring all the writers he will never know, and... if this book was somehow inspired by Douglas Adams? Holy shit, it feels like they misread and failed to grasp the story beyond "it's in space."

2. I don't know why I should care about any of the characters at all. Mallory has no personality beyond "always runs from things" and paranoia, which... isn't a personality. Adrian is basically "asshole politician" as a flat character. Xan has been given nothing beyond "some stereotypical traits of a military man who absconded." None of these people have thus far had any interesting introductory character traits given to them.

3. The alien's name is STEPHANIE. Even Xan's name is more interesting. What the fuck is Stephanie for an alien? And why not even try alien-stylising it or something like Steif'any. Which is still cheesy as fuck but is at least VISUALLY INTERESTING. (It's like being inspired by Douglas Adams didn't help with silly names, which all of the aliens in Hitchhiker's had!)

4. Chapter titles referencing media miss the point of the mentioned stories? Chapter 1 asks "Was Sherlock Lonely?" as it describes the ways in which Mallory is lonely because people keep getting murdered around her, meaning she tries to stay away from people to avoid them getting murdered. (Sidebar: I don't know how other species aren't impacted by this... or how the other two humans around her haven't been murdered, either... I'm guessing it's so the premise of "humanity is coming, oh no!" works in the story, which is... kind of absurd.) But if Sherlock was lonely, it was not because people were dying around him; he was lonely because he felt out of place due to his abilities and many people didn't understand him, which is why (I think) the friends he latched onto were those so willing to tolerate his strangeness. Which... wasn't nearly as strange as most adaptations made it out to be?

Addendum: I think the failure in making interesting characters is a failure in understanding both of the genres. Mysteries often have characters that receive less exposition, which is either built up throughout the novel as you explore the mystery or simply not present in the name of focusing on the story (which is fine). This is generally not true of the detective (especially if that detective exists within a series). Science fiction often requires exposition to set a lot of scenes and characters, though that's not always necessary (some things just are, but other things have to explained). The juxtaposition here is that... you need to actually do both to an extent, and Lafferty doesn't seem to have engaged with either genre to understand what works (not as necessity but as inspiration).