In the foggy backstreets of Victorian London, three clever kids and their scrappy alley cat dive headfirst into the wildest adventure of their lives! Billy dreams of becoming the city’s greatest detective, reckless Tom never hesitates to charge straight into danger, Watson is always ready to bare his claws, and Charlotte, better known as Charlie, always has a brilliant idea up her sleeve. Together, they’re the Baker Street Four! But when they cross paths with Sherlock Holmes, the fearless foursome is swept into a case that threatens the very crown of the kingdom.