“Book Descriptions: Gallifrey is in a state of crisis, facing destruction at the hands of an overwhelming enemy. And the Doctor is involved in three different incarnations - each caught up in a deadly adventure, scattered across time and space. The web of time is threatened - and someone wants the Doctor dead.
The three incarnations of the Doctor must join together to set time back on the right track - but in doing so, will they unleash a still greater threat?
Chronological Placement: This story takes place between the television adventures, The Five Doctors and Warriors of the Deep (Fifth Doctor segments); between The Trial of a Time Lord and Time and the Rani (Sixth Doctor segments); and prior to the TV Movie (Seventh Doctor segments).” DRIVE