Ever read "The Doctor and the Enterprise"? Fun stuff....
It's also a crossover with Marion Zimmer Bradley's Darkover novels. (The planet they visit is "Lightunder." Get it? Darkover. Lightunder. Yeah, subtle.)
I think
TDatE is okay. Kirk is pretty badly handled. I'm also not sure how well Airey knew her
Doctor Who, as she deals with something that
The Three Doctors dealt with, namely the mental blocks the Time Lords put in the Doctor's mind after
The War Games.
The sidequel, "The Lieutenant and the Doctor," is, umm, okay, yeah I read it. I spent a few years tracking it down, and when I found it, it wasn't what I was expecting -- namely, that
TDatE sets up the A&A officer, Dorcy Stephens, as a potential companion-like character. I assumed that "Lieutenant" took place after
TDatE, that perhaps Stephens stowed away on the TARDIS. Instead, the story relates some of the events on Lightunder from Stephens perspective, particularly her sexual relationship with the Doctor. If I could unread a story, I would. It's not terrible, but it changed my perspective on the original.