In Vagabond, he returns to England to try to uncover the Grail's whereabouts and helps defeat the Scottish invasion of 1347.

He discovers that his cousin, Guy Vexille, is working with an ambitious French cardinal to obtain the Grail for their own ends.

He is trapped in a castle he had captured, but an outbreak of the Black Death causes many of his besiegers to flee, and Thomas fights his cousin on more even terms and kills him.

However, his liege lord hears stories about la Malice, the sword used by Peter to defend Jesus in the Garden of Gethsemane, and about its powers, so once again Thomas is ordered to find another holy relic.

Thomas of Hookton is later briefly mentioned in Cornwell's novel Azincourt, set around the events leading up to the Battle of Agincourt in 1415 as having "died as a lord of a thousand acres."