Rebel Winter by Steve Parker
On the brutal battlefields of the 41st Millennium, the life of an Imperial Guardsman is harsh and short. On the snowy wastes of Danik's World, a regiment of Vostroyans is ordered to hold their ground to protect the retreat of other Imperial forces. When their own orders come to move back, they discover they have been stranded behind enemy lines. Cold, hungry and running out of supplies, trapped between rebel forces and hordes of orks, can the Guardsmen ever fight their way back to safety?