For the first time, this book explains in detail and credibly about the unknown heroes of an underground movement in the camps. It describes examples of courage such as the activities of General Dmitry Karbyshev, the creativity of poet Musa Jalil, the work of the “Brotherhood of Prisoners of War (BSPW)” (БСВ), and the escape from the “block of death” in the Mauthausen concentration camp. These materials were used as evidence at the Nuremberg trials against Nazi criminals. The publication is not devoted to the horrors of concentration camps; instead, it demonstrates manifestations of heroism by prisoners of various nationalities who resisted the fascist regime. Many former prisoners left no accounts of what they had endured, which makes this book especially important. The authors offer readers essays about forgotten heroes and little-known events of the Resistance movement, giving an opportunity to rethink aspects of history that have already been studied.