Geraldine McCaughrean's The White Darkness is the story of Symone Wates, a deaf 14-year-old girl, who is a complete misfit at her school, and whose best friend is the long-dead Captain Titus Oates. Her "Uncle" Victor (who is in fact her father's business partner) takes her to Paris; initially Sym's mum is going with them, but Victor pockets her mother's passport. Once in Paris, however, Victor suggests that they go to the South Pole instead as he believes in the 1818 theory of John Cleves Symmes, of a Hollow Earth (which envisions the Earth as a shell about 800 miles thick, with openings at both poles about 1400 miles across. Symmes believed there were four inner shells also open at the poles), and he wants Sym (who discovers that she is named after Symmes) to help him discover Symmes' Hole, as the entrance is known. Sym also discovers that her father, before his death, had stopped believing the theory and that Victor murdered her father with the supposedly healing herbal teas he had been giving Sym's father. Sym has believed for a long time that her father didn't love her and was disappointed in her, but Victor's revelations of her father's murder (so that he could cash in Mr Wates' life insurance and cover up the fact that he has been robbing Sym's family blind for years) cause her to rethink her view of her relationship to her father.
After they arrive in Antarctica, Victor reveals the supposed existence of Symmes' Hole to Sym, and introduces his fellow believes, Manfred Bruch, a film producer and his "son" Sigurd, who are not related and are not really from Norway either. Bruch tries to con Victor out of the finances Victor has given him for the documentary film Bruch was supposed to be making about Victor's "Great Discovery", but Victor is too good at deceiving others to be deceived himself. The bankers' draft that Bruch holds is worthless, and Victor prevents Manfred and Sigured from flying away by blowing up the weekly plane that has come to the Camp. He has also given everyone except himself, Sym, Manfred and Sigurd one of his herbal concoctions, leaving them to sleep so that the four of them can go off with the big Hagglund truck in search of the portal. Manfred reveals his attempt to con Victor, but Victor has suspected him all along and has been giving Bruch his special "teas" since they left camp, and he eventually abandons Bruch out on The Ice, once the latter asks that they turn back to the camp.
Victor reveals his intention that Sym and Sigurd meet the aliens whom he believes to be living inside the earth and that they will be the outside world's ambassadors (and that they will have children to maintain the line of contact). Sym has been having grave doubts about Victor before he reveals that he was responsible for her father's death, and then she realises that Victor was also responsible for Sym going deaf, when he is supposedly "training" Sym for the role he has planned and gives her strong antibiotics that cause her to go deaf. She and Sigurd consider killing Victor and driving the Hagglund back to the Camp, but they decide they cannot kill Victor. However, when they stop for a refueling break, Sigurd goes off, supposedly to go to the toilet, but instead he pretends to have found Symmes' Hole. He fools Victor who clambers down into an ice hole and becomes trapped there, whilst Sigurd goes off with the Hagglund. Sym finds herself alone on The Ice, and attempts to retrace their path back to the Camp. Eventually she catches up with Sigurd, who has stalled the Hagglund and then caused the engine to overheat so that it melts (a fact Sym finds irresistibly funny, given their location). Sym is convinced they will die, but one of the women from the tourist group at the Camp finds a postcard that Sym had left with her for her mother and people are sent in search of the four missing persons, arriving just in the nick of time to save Sym and Sigurd at least.
Throughout the book, Sym talks frequently to Titus Oates with whom she believes she is in love, even though he's 90 years dead and only exists in her head. She has regular conversations with Titus, and after Sigurd has abandoned her and Victor, and she (in turn) has left Victor behind, she gives him her pain to carry, believing she can see him pulling it on a sled as he walks alongside her and encourages her to keep moving.
This is a fabulous book about the dangers of obsession (whether with a crackpot pseudo-scientific theory, or with a long dead polar explorer), and a coming-of-age story too (there is no doubt that Sym matures a great deal during her experiences). It's also a gripping, tense thriller that keeps the reader turning the pages.