Serpentine follows Lyra Silvertongue as she returns to Trollesund, the remote town where she first met the armoured bear Iorek Byrnison and aeronaut Lee Scoresby in Northern Lights. The story sees Lyra and her daemon Pantalaimon older and a little wiser, and in search of an answer to a shocking, secret condition - their ability to separate - from the witch-consul, Dr Lanselius.
Fantasia