“Assailed by violent bolts of multi-coloured energy, the TARDIS is blasted off-course and forced to land on the barren planet of Lakertya.
The turbulence brings about the Doctor’s sixth regeneration. But that is the least of his worries. He has been hijacked by that ruthless renegade Time Lady, the Rani.
Why has the Rani brought the Doctor to Lakertya? What are the hideous Tetrap guards? Who are the eleven geniuses she has imprisoned in her stronghold? What is the vital significance of the asteroid of Strange Matter? And can the Doctor stop the Rani’s diabolical scheme before it affects the whole of creation throughout time and space?”
Time and the Rani was a novelisation based on the 1987 television serial Time and the Rani. This first adventure of the Seventh Doctor was also the first novelisation of his era to be published; this was only also true of the Third and Fourth Doctors – all other Doctors had later stories published as their first novelisations. [tardis.wikia.com]
Written by Pip and Jane Baker, the novel features a longer finale for the Sixth Doctor (and reveals that the regeneration into the Seventh Doctor was caused by “tumultuous buffeting” when the Rani attacked the TARDIS), while the Tetraps seem to speak English backwards. [Wikipedia]