The 6th book in the series. Recovering from injuries both physical and mental which she had suffered a year ago, Sandra Swift is outwardly a placid shadow of her former self. But her thoughts and dreams are plagued by personal demons, A possible solution arrives in the form of a mystery from the Arctic. A crashed airplane is discovered to have been carrying an unusual cargo of iron pellets. Curiosity soon ignites a long-forgotten spark within Sandy's spirit and, accompanied by Phyllis Newton and Bingo Winkler, she sets out to find answers. Before long she's involved in an undersea mission on behalf of the Russian government. There she encounters treachery, an attempt on her life and comes face to face with a figure possessing a background straight out of legend. As Sandy becomes hunted by a modern-day navy she travels to places she never thought she'd see, trying to make allies out of long-time enemies. A race is on to prevent a plan that could result in ecological disaster, as well as possible nuclear annihilation, and on the coldest place on Earth, Sandy finds herself facing the hottest action.