The Hidden World is the fifth book of Judy Allen's chapter book spin-off of the Watership Down TV series.
Backside[]
Hazel, Fiver and Hawkbit fall down a hole in a burrow and end up in a strange new world of caves, leading directly to the heart of Efrafa. Outside, Bigwig is sure they have been kidnapped by Woundwort and goes off to Efrafa, to fight for his friends.