Children of the Shaman: A Journey through Ice and Time (Mir: Shamanworld Book 1)

An ancient power returns.
A world is trapped in time and snow.
The only hope: a young outcast.
In the remote interior of Lefranu someone - or something - has been killing railway workers. Driving a tunnel under the forest, they have started to die, horribly.
Yuda Vasilyevich, a shaman, is sent to investigate.
Yuda brings with him the teenage children he deserted when they were small: spikey Annat, a shaman like her father, and bookish Malchik, who has not forgotten his father’s mistreatment of their mother.
When Malchik is drawn into the underworld, Yuda and Annat set out to find him; so begins a perilous journey into a world of ice, with danger ahead and an implacable enemy behind them. Only they can solve the mystery and defeat the power of the Cold One.