Red sky at noon
(Book)

"Imprisoned in the Gulags for a crime he did not commit, Benya Golden joins a penal battalion made up of Cossacks and convicts to fight the Nazis. He enrolls in the Russian cavalry, and on a hot summer day in July 1942, he and his band of brothers are sent on a suicide mission behind enemy lines-- and there may be a traitor among them. The only thing Benya can truly trust is his horse, Silver Socks, and that he will find no mercy in onslaught of Hitler's troops as they push East." --,(Source of summary not specified)