Everyone has a purpose and everyone has a meaning to life, but what is the Doctor's purpose? Ever since he left his homeworld of Gallifrey, the Doctor has been drifting through Time. But now, it's time to face what he has become, because today, the Doctor returns home to face his past... and his present... and possibly his future.
- Steven didn't take HiFi when he left the Doctor.
- The TARDIS's fault locator has broken down.
- The Doctor's ring had a part in his escape from Gallifrey.
- Susan is mentioned, and she is said to take after her mother.
- K'anpo gave the Doctor back his Five Hundred Year Diary.
- This story contains a short flashback to a previous meeting of the Doctor with his mentor at the age of thirty.
- At the end of The Smugglers (Ben and Polly's first trip in the TARDIS) the Doctor states that the TARDIS has landed in "the coldest place in the world." In 1966, this was intended to be Antarctica to lead into The Tenth Planet. The Three Paths effectively retcons this by having the TARDIS land in snowy mountains on Gallifrey instead of Antarctica. As such, it creates more narrative breathing space for stories featuring Ben and Polly as companions of the First Doctor before his regeneration. Before The Three Paths was published, Food for Thought, Ten Little Aliens and Five Card Draw had already depicted further adventures of the First Doctor, Ben and Polly than the TV series had originally accommodated for.
- Ben and Polly do not accompany the Doctor in this story; they remain in the TARDIS, sleeping.
- Bobby Zierath is remembered by the Doctor. (PROSE: The Schoolboy's Story)
- The Doctor wears his fingerless gloves, worn by him previously in PROSE: Roses and TV: The Five Doctors.
- The Doctor is referred to by his Academy nickname, Theta. (TV: The Armageddon Factor, The Happiness Patrol)
- The Doctor is initially afraid of regeneration, similar to his tenth incarnation. (TV: The End of Time)
- The Doctor is given back his diary. (TV: The Power of the Daleks, The Tomb of the Cybermen et al) He drew pictures of Torvic in his diary. (AUDIO: Master)