What a weird and wonderful book! 
 All the Birds in the Sky mashes together magic and crazy science to create a whole that's odd and unique and utterly engaging. We first meet the lead characters Patricia and Laurence as outcast kids -- bullied, friendless, and with home lives that just scream abuse. When they finally meet, they provide each other with refuge and support, but ultimately part ways until a seemingly random reconnection as adults. 
 The story switches perspectives between both characters, showing us the life of Patricia the witch, cursing and healing people, always being cautioned against the #1 sin for witches, Aggrandizement... and Laurence, the genius mad scientist working on anti-gravity and the possible salvation -- or destruction -- of the planet. 
 The writing is often quite funny, although the subject matter can get pretty heavy, what with the impending end of the world and all. The witches and the scientists have plans to save everyone, but each plan may also bring the apocalypse. Patricia and Laurence battle their own factions as well as each others' in order to avert disaster, even while dealing with their own inner turmoil and competing interests and emotions. 
 This book truly brings together science fiction and fantasy in a way very few do. If you enjoy oddball fiction with a science-y, magical flair, check out All the Birds in the Sky! 
 PS - Bonus points to Charlie Jane Anders for making excellent use of San Francisco -- not just the obvious tourist attractions, but all the odd little corners and neighborhoods that make SF so SF!