Sir Terry Pratchett fans: Final book 'devastating'

The final novel by author Sir Terry Pratchett has been released, almost six months after his death.

The Shepherd's Crown, the 41st novel in his Discworld series, went on sale in the UK and Commonwealth at midnight BST (23:00 GMT Wednesday).

Shops opened at midnight and included Waterstones in Piccadilly, central London, where the author's friend Rob Wilkins read an extract to 200 ticket-holders.

WARNING: some plot details may be revealed