May Books 17) Tip of the Tongue, by Patrick Ness
"Honestly," Nettie said, shaking her head again. "The lies people tell themselves and call it the truth."
These wee Puffin Doctor Who ebooks are having a good run right now. Here we have the celebrated Patrick Ness, delivering a very solid tale of two marginal teenagers in wartime Maine, finding themselves dealing with a peculiar fad for truth-telling gadgets which turn out to be alien tech, with a mysterious celery-wearing stranger and his scandalously dressed companion all mixed up with it as well. This is the first of the books in this series which is not told from the tight narrative viewpoint of Doctor or companion, and all the better for it.