Key to Time

The Key to Time is a powerful and mythic artifact with which The Guardians of Time used to maintain control over universal order and chaos.

It was first created to wiped the memories of the participants of the Millennium War, though it later gained a more general purposes. (DW: The Quantum Archangel) It's shape was that of a perfect, crystal-like cube. When the balance was upset, White Guardian enlisted the help of the Fourth Doctor and Romana to gather the Key's six segments. (DW: The Ribos Operation) The Black Guardian used the Shadow to stop the Fourth Doctor from obtaining the sixth segment. After The Doctor defeated the Shadow, he assembled The Key and outwitted the Black Guardian, enabling the White Guardian to restore universal balance. The Key to Time was then broken apart and scattered throughout the universe again, presumably assuming five new shapes and restoring Princess Astra to her natural form. (DW: The Armageddon Factor)

Disguised Sections

 * A lump of jethrik taken to Ribos by Garron (DW: The Ribos Operation)
 * The planet Calufrax, shrunk to football size by the planet Zanak. (DW: The Pirate Planet)
 * The former Great Seal of Diplos, kept in the form of a necklace on Earth by Cessair. (DW: The Stones of Blood)
 * A Taran statue. (DW: The Androids of Tara)
 * A holy relic of the Swampies, swallowed by Kroll on a Delta Magna moon. (DW: The Power of Kroll
 * Princess Astra of Atrios. (DW: The Armageddon Factor)