A deadly conspiracy from Mars succeeds in stripping Ivanova of her command and forcing the Babylon 5 loyalists into action.
Even though it's based on the TV show, it definitely could have been a stand-alone book. All the information based on the series is explained shortly and a person with no knowledge of the show can understand it easily.
Almost all the book is very well written, except for one part where the author shows a "trashy" side, when Garibaldi holds Ivanova and feels attracted to her, and feels "her feminine body shivering". The author stopped herself at the right time, not writing sleezy lines, and getting back to the problems of the investigation.
This is the best book of the Babylon 5 novel series, and for Babylon 5 fans it is very highly recommended, a "don't miss" book, and for non-fans it's recommended, a "can read" book.
The events take place after "The Coming of Shadows" and before "All Alone in the Night".