The young adult suspense thriller, published in 1994, reunites L'Engle's most frequent protagonist, Vicky Austin, with Adam Eddington, both of whom become enmeshed in international intrigue as they travel separately to Antarctica.

[citation needed] The story takes place several months after the end of A Ring of Endless Light, the novel in which Vicky and Adam first met.

Despite Vicky's concerns about an apparent cooling in Adam's affection for her, it is established that their everlasting romantic relationship is quite a strong and close one.

Part of the story takes place in Vespugia, the fictional country first mentioned in A Swiftly Tilting Planet.

The events of that book have a strong bearing on the dangers Vicky faces approximately thirteen years later.