https://www.theguardian.com/books/2020/jul/09/philip-pullman-his-dark-materials-novella-serpentine-october

Written in 2004 and auctioned for charity, Serpentine sees an adult Lyra and her daemon Pantalaimon revisit Trollesund in search of secrets

A previously unseen His Dark Materials story about a teenage Lyra, written by Philip Pullman over a decade ago and that he never intended to publish, will be released this autumn.

Serpentine, out in October, 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. A novella, it is set after the end of the trilogy His Dark Materials, but before the start of Pullman’s recent book, The Secret Commonwealth. 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”, revealed the publisher, Penguin Random House Children’s.