Sixth graders Jack and Ruthie return in their third adventure in the Art Institute of Chicago's magical Thorne Rooms! During a school presentation, Ruthie and Jack discover that their classmate Kendra is descended from Phoebe Monroe, the young slave they befriended when they traveled to 19th-century South Carolina. Kendra tells them that long ago her family lost their good name and their business selling herbal remedies when mobsters accused them of stealing the recipes! Only Ruthie and Jack know the truth—because only they know about the secret ledger that Phoebe wrote the recipes in long ago! Ruthie and Jack's mission to clear Kendra's name takes them back to the Thorne Rooms, where a mysterious old coin leads them to 1753 Cape Cod and to Jack's own ancestor . . . the pirate Jack Norfleet! But playing with history can be dangerous! Suddenly, Jack's very existence is in jeopardy! Can Ruthie and Jack find the proof they need to help Kendra? And can they fix the past and save Jack's future . . . before it's too late?