Burn, by Patrick Ness

Not so much an alt-history as an alt-reality, this is a fascinating reimagining of the cold war era, with added dragons. Humans and dragons have lived an uneasy truce for the last couple of centuries, after a history of conflict. The peace is threatened when a group of human dragon-worshippers, known as Believers, look to enact an old prophecy. Fanatical disciple Malcolm travels across country, pursued by the FBI, to carry out his destiny. Will a chance encounter lead him astray? Meanwhile Sarah, a vulnerable mixed-race farm girl forms an unlikely friendship with the snarky dragon her father employs to clear their fields. There is rather too much foreshadowing and when the story threads and characters all come together half way through the book, the story takes a sharp turn into an alternate universe. The trick to world building or alternate realities in speculative fiction is to establish clear rules and stick to them. Doing this well allows suspension of disbelief to the extent that literally anything is possible. Unfortunately Burn does not achieve this. There are lots of interesting elements and characters, but they don’t come together as a credible whole.