When Sally Jones and The Chief discover a curious rose-shaped necklace hidden onboard their beloved Hudson Queen, it's the start of another perilous adventure for the seafaring gorilla and her faithful friend. Determined to get to the bottom of the mystery, they set sail for Glasgow, but there fall into the clutches of one of the city's most ruthless gangs, commanded by a fearsome smuggler queen who will stop at nothing to snatch the necklace for herself.

Held prisoner hundreds of miles from friendship and safety, Sally Jones must use all her strength, determination and compassion to escape and unravel the mysterious story of the False Rose - a twisting tale leading all the way from Lisbon to Shetland and the South Seas.