An amoral, scientific genius, the Rani was a renegade Time Lord, and contemporary of both the Doctor and the Master. She was forced to leave Gallifrey when an experiment on mice created monsters, that ate the Lord President’s cat. Setting up empire on Miasma Goria and experimenting on its inhabitants, she made regular visits to Earth for human brain fluid. On one such visit, she was interrupted by the Doctor and the Master, and eventually trapped with the latter and a growing Tyrannosaurus Rex embryo in her TARDIS. Escaping this, she set about a new plan to channel the intellects of geniuses from across the universe – including the Doctor’s – into a giant brain. Foiled by the Doctor she was trapped in her TARDIS by the Tetraps.