Doctor Who: The 50th Anniversary Collection

While on a quest to find the six disguised segments to the Key to Time, the Doctor and his new assistant encounter con men plotting to sell the planet Ribos as a valuable resource-swindling a vengeful ruler that endangers them all.

Part 2 of "The Ribos Operation".

Part 3 of "The Ribos Operation".

Part 4 of "The Ribos Operation".

The tracer has detected the second segment on Calufrax. On arrival, the travelers discover Calufrax and other planets have been 'jumped' for their mineral wealth by the planet Zanak. And the Doctor can't believe who is next on their list.

Part 2 of "The Pirate Planet".

Part 3 of "The Pirate Planet".

Part 4 of "The Pirate Planet".

On the planet Delta Magna, the Doctor is shot at while he attempts to get an accurate reading on the tracer. Meanwhile, Romana is abducted by the Swampies. The drama builds as Kroll, a giant squid-like creature, suddenly appears and starts to attack.

Part 2 of "The Power of Kroll".

Part 3 of "The Power of Kroll".

Part 4 of "The Power of Kroll".

The Doctor and Romana trace the sixth segment to Atrios and the Doctor finally completes the Key. When the White Guardian arrives to claim the Key, the Doctor must decide its fate.

Part 2 of "The Armageddon Factor".

Part 3 of "The Armageddon Factor".

Part 4 of "The Armageddon Factor".

Part 5 of "The Armageddon Factor".

Part 6 of "The Armageddon Factor".