Billie and her friends dare each other to explore the spooky house at the end of the street. They are sure it's haunted. So scary! But if anyone can handle ghosts, it's Billie B Brown!

One day Billie and Jack find a note hidden under a rock at school. It seems to be written in code! It’s time the two friends put their code-breaking skills to the test.

Billie and the Secret Mystery Club have a new case to solve. Who has put leaves in Rebecca's sandwich? It’s a real mystery. Soon everyone suspects Benny, but could they have the wrong kid? It’s up to the SMC to find the real culprit!

Someone has stolen all of the ripe strawberries from Mika's garden! The Secret Mystery Club is determined to work out who it was. Could it have been the gardener? Or was it the neighbours who just made a batch of strawberry jam? Whoever it was, they won't get far – not with the SMC on the case.

Someone has taken something from the principal's office at school! Who would have done such a terrible thing? And when one of Billie's friends becomes a suspect, will Billie even know who to trust anymore?

Billie and the Secret Mystery Club have been given a very important mystery to solve for the principal at school. A long time ago, a time capsule was hidden in the school somewhere, and it's up to the SMC to find it!