Patsy Cline is becoming best friends with another girl! It looks like Penelope is going to lose Patsy to Vera Bogg...forever.

So Penelope starts a secret museum full of things that remind her of the people she loves, in case she loses them, too.

Lizzie Maple, who loves adventures, is on board to help. But other people seem to think 'taking their things for a museum' is the same as 'stealing'... and Penelope is suddenly in a whole lot of trouble!Can Penelope win back Patsy Cline? And can she figure out a way to create her memory museum without stealing things?