Jason is all set to spend his summer vacation relaxing at home in Boston, until his estranged Grandmother dies and he has to travel to St. Petersburg, Florida to help his dad clean out her house. His Grandma has always been a bit of a mystery, in fact Jason never meet her, and during most of his dad's childhood she hadn't been around, so they didn't talk about her much. However, the mystery gets even more mysterious, and a little dangerous, with each passing moment Jason spends in Florida. At the funeral, the funeral director calls his Grandma, Marnie, her name was Agnus; then while cleaning Jason finds an old magazine Bizarre Mysteries with a story called Twin Palms, about a girl named Marnie, written by Emerson Beale, whom his dad says was an old friend, maybe boyfriend, of his Grandmothers. A strange phone call and an old postcard start Jason, and his Grandmother's neighbor, Dia, on a clue hunt for the next chapters of Twin Palms, a hunt that will reveal a lot more than just what Emerson Beale typed next.
 
"I thought then how we all have stories. Sometimes they're so short you could fit them onto the back of a postcard. … Other times they're so long they take a lifetime to write before they are finished. And sometimes everything that happens is connected to everything else that happens, and the stories are so big and long and deep they never finish. I like that kind the best." Jason pg. 358 The Postcard
 
Jason thought his summer was ruined, and when you got your summer reading list from school, you probably felt the same, but give The Postcard by Tony Abbott a chance, (like Jason gave Florida a chance) and you just might find it's not so bad.