The navigator by Eoin McNamee

HarperCollins, 2007.
(Age10+) Owen is a loner, shunned by other people because of his father's supposed suicide and his mother's inability to cope. He seeks refuge in his Den, but one day is accosted by a tiny man, the Sub-Commandant, who takes him to a group of people called the Resistors. Owen finds himself caught up in a battle between the Harsh, an eerie group who use the cold to turn back time, and the Resistors who are fighting to keep time normal.

McNamee has gathered together an interesting cast of characters. Owen comes into his own, and begins to understand the meaning of courage and sacrifice. Cati and Wesley, Owen's new friends, are brave and feisty. Dr Diamond is an eccentric inventor who speaks backwards when time affects him and the evil Johnston and his cohorts are convincing villains.

Boys in particular will enjoy the inventive machinery and the exciting trip to the frozen north, while trying to work out what the Mortmain is and why it is vital to the outcome of this fight of good versus evil.
Pat Pledger