A review by brian
Forgotten History by Christopher L. Bennett

4.0

The Department of Temporal Investigations (DTI) are set up to prevent changes to the timeline having the effect of changing or wiping out history.
This book covers several storylines from the original series and the first Star Trek film.
A mysterious ship resembling the Enterprise but bearing DTI markings is found after activating a distress call.
Various alternate timeline races want to get their hands on it to give them an advantage.

Switches between original series era and the TNG/DS9 etc period, showing the DTI in its early days and also the "now" where they have a clear idea of what they are working to protect.

A fair bit of "techno-babble" makes it tricky in places, but the characters are done well and the different episodes are explained in a way that makes them part of a wider picture.

There's behind the scenes politicking as members of the newly formed DTI want to use time travel for their own ends, and the later period where the DTI members think Kirk and his crew are trampling all over the space-time continuum.