Lair of the Skaven Warhammer Adventures: Realm Quest Series, Book 2

Epic heroes, mighty armies and terrifying monsters clash against the backdrop of magical landscapes. When their master, Vertigan, is kidnapped, Elio and his friends are determined to try and rescue him. Using a powerful artefact, they forge a magical doorway into a forbidding underground world teeming with Skaven ratmen! Hopelessly outnumbered, Elio, Kiri, Alish, Thanis and Kaspar must use all of their cunning if they are to find Vertigan and escape alive