Posing as a papal nuncio, the troll Vilius "The Vile" Vilutis haunts the Cumbrian hills in search of the magical onyx with the potential to revolutionize smartphones worldwide, aiming to put his enemy, Silicon Valley gazillionaire Zingy Splitz, out of business forever. Suspicious, Zingy contacts Pope Benny in Rome, where rumour has it Vilius once worked, thus discovering the troll's current whereabouts.

Meanwhile, in their bucolic farmstead in Cumbria, the elves Mordy and Hazchem team up with PAX (Pagans Against Xmas) to ensure the onyx's safety, but two ghastly hangings disrupt the peace. The Vatican is implicated in the crimes, its motives darker than Vilius's vindictiveness. And the troll is not, after all, as vile as he might have appeared.