This short story is a continuation of the short story The Lost One and novella The Wind Off The Small Isles by the much-loved writer Mary Stewart. It borrows some of the characters of those two stories in order to 'finish' the tale, in an attempt to satisfy the author's original intention of creating three 'Perdita' stories.

Perdita West was first seen in The Lost One (a short story which itself was 'lost' for many years) as a young woman tackling a dangerous situation in a lonely country spot in Northumberland, aided by her irrepressible mother. In Wind Off The Small Isles, Perdita took a job as an author's assistant and travelled to the picturesque island of Lanzarote, where she explored the island's history, was swept off her feet by a dashing young man and got herself into a dangerous situation when skin-diving in underwater caves. The Sea Raven picks up Perdita's story some years later, when she makes a ferry journey to the Shetlands and unexpectedly meets an old acquaintance...