Twelve-year-old Ava finds an old pencil in her family's junk drawer and discovers, during a math test, that it will answer factual questions, so she and her best friend Sophie have a great time--and Ava grows in self-confidence--until the pencil reveals a truth about her family that Ava would rather not know.

Told from his point of view, continues the love story of Bennett, a time traveler from 2012 San Francisco, and Anna, sixteen, of 1995 Evanston, Illinois, as they try to make their relationship work despite his fear that it is not meant to be.