I (Iterations of I)

The I was an entity that existed on a plain of existence tangentially connected to N-Space. It was described as being analogous to a sentient number, with its true nature being virtually incomprehensible to both humans and Time Lords.

A cult which believed God was an impossibly long number accidentally captured the I on Fleming's Island off the coast of Ireland in 1981. This attracted the I Predator to the area, which hunted and killed all the cultists. When the TARDIS landed on the island in December 1981, the Fifth Doctor and Adric freed the I, and the I in turn helped the Doctor and his companions to escape by luring and trapping the I Predator in a feedback loop generated by a calculator. (AUDIO: Iterations of I)