The Tale of Beowulf
From Tardis Wiki, the free Doctor Who reference
The Tale of Beowulf was the story of Beowulf. The Seventh Doctor read it in both the White and Black TARDISes before leaving his two pairs of companions. They used the book on his armchair in both TARDISes as proof that they both came from the same time.
Ace studied it at school but only paid attention due to the fighting. (AUDIO: Black and White)
