The chase is on when Isabella and Bob track down their elusive foe!

She's a girl who knows how to handle any situation. Cool as a cucumber, quiet as a mouse- she's got a smile so wide, you can't help but be charmed!

Get ready for an undercover operation in Isabella's Big Adventure: Trouble in Whitefall Tower! This fifth book sees Isabella and Bob embarking on a three-month-long undercover mission during a hot summer to get closer to their elusive foe, the mysterious 'B.D.'. This time, they're not just reacting to a sudden adventure; they're proactively trying to stop B.D.'s revenge.