The Doctor solves the murder mystery and finds the final missing key.
Arriving in Millennius, Ian is put on trial for murder.
In a snowy wasteland, Vasor, an unscrupulous trapper, imprisons the travelers.
Ian and Barbara find a temple in the middle of a hostile jungle.
In the city of Morphoton, the Doctor, Barbara, Ian and Susan are welcomed as guests.
The TARDIS lands on a remote island, surrounded by a sea of acid.