A fabulous gothic tale of three young cousins who are summoned by their evil Uncle Silas to spend the summer with him at Sommerset - his grand gothic estate perched on a mysterious island surrounded by an alligator-infested swamp.

Silas Winterbottom, who has had virtually no contact with his extended family for decades (except to insult them or refuse their requests for money), is dying. It is his intention to select an heir from among his nieces and nephew - Isabella Winterbottom (13), Adele Fester-Winterbottom (12) and Milo Winterbottom (12).

The Winterbottom children have very different backgrounds but each of them have motive for accepting Silas invitation: Adele's family have been forced into exile in Tipping Point, Tasmania due to her mother's unethical experiments with prize-winning poodles; Isabella and her father are accomplished criminals living a fraudulent life among London's social elite and finally; Milo, orphaned after his parents were lost in a volcanic eruption, lives with his grandfather the Maestro in a tiny basement apartment in Wales.

One of the Winterbottoms believes Uncle Silas is a murderer; two of them will do anything to win his favour and his fortune... and only one will be chosen.