The Target Doctor Who books. For a generation of pre-video Doctor Who fans, the Target books were the only way to get episodes of Doctor Who they either hadn’t seen in years or hadn't seen at all. Some were, and still are, some they’d never actually get to see due to being lost, presumed destroyed.

The TARDIS materializes in a frozen wasteland and the Doctor doesn’t know where or when he, Ben, and Polly have landed. Within minutes of exploring, they are captured by a humanoid patrol and are taken to an underground facility that turns out to be ...

Intending to bring his Australian flight attendant companion, Tegan Jovanka, home to Heathrow Airport in 1981, the Doctor lands the TARDIS in the right place, but in the wrong time.

From The Doctor Who Reference Guide:

The Doctor, Ben and Polly arrive on a beach in 17th century Cornwall and soon become caught up in a web of intrigue. Pirates led by the villainous Captain Pike are searching for a hidden treasure, while a smuggling ring led by the local Squire is trying to offload contraband.

A relief ship en route to Titan passes through and is attacked by a mysterious cloud. The TARDIS receives a May Day and passes through the same cloud and is attacked. When the Doctor is infected by a virus bent on domination, it is up to Leela to save the day, with a little help from a new friend.