
In episode 2, the four youngsters make friends with Tassie, a mysterious gypsy living in the woods with her mother, who is threatened by Sam, nicknamed Scar. During the holidays, they live with Philip and Dinah's mother, Allie at Spring Cottage which she borrowed from her friend (no longer set in Scotland as in the original novel). The names of the children are Philip and Dinah Mannering who are brother and sister, Lucy-Ann and Jack Trent, also brother and sister.

The series was filmed on location and at Saltwood Castle in Saltwood, Kent. The plot of the series closely followed that of the novel, but the setting was updated to the time of its production. Terry Marcel, Rosie's father was the director. Lionel Augustus and Edward Francis (who was the producer of all episodes) were the writers. The children were played by Rosie Marcel, Richard Hanson, Hugo Guthrie, Bethany Greenwood and Eileen Hawkes.

The star-studded cast included Susan George, Gareth Hunt and Brian Blessed. It ran for 8 half-hour episodes from 19 April – 7 June 1990, produced by TVS Films and shown on CITV. The Castle of Adventure was a children's live-action serial based on the book by Enid Blyton. Along with Bill Cunningham, who appears later in the book, the children manage to expose a ring of spies led by the threatening Scar-Neck who are working against the UK Military service. The four youngsters make friends with Tassie, a mysterious gypsy living in the woods with her mother. Jack, Lucy-Ann, Dinah and Philip attempt to figure out what is behind the strange goings-on at a ruined castle near Spring Cottage in Scotland where they are on holiday with Dinah and Philip's mother, Aunt Allie.

The first edition of the book was illustrated by Stuart Tresilian.

It is the second book in The Adventure Series. The Castle of Adventure (published in 1946) is a popular children's book by Enid Blyton.
