databank
900 year diary
randomiser
After the Doctor scattered the reassembled Key to Time, he earned the Black Guardian's eternal enmity. The Guardian swore to track him down, so the Doctor fitted the TARDIS with a Randomiser, believing that if he did not know where the TARDIS was going, the Black Guardian certainly would not be able to follow. However, while on Argolis, the Doctor needed to cannibalise the Randomiser to ensure the success of the Recreation Generator and thereby reverse the aging process he suffered from. As a result, the Black Guardian was eventually able to track the Doctor down in an attempt to have his revenge.