This is certainly among the most stifling war movies I’ve come across. The film takes place almost entirely in the sewers under Warsaw as German forces move closer during the early days of World War II. "Zadra" (Wienczyslaw Glinski) receives an order from his colonel to get what remains of his unit – now more like a platoon than a company – to somewhere they can hopefully reorganize and keep battling against some very difficult circumstances. With the resourceful "Stokrotka" (Teresa Izewska) and his dependable second-in-command "Korab" (Tadeusz Janczar) assisting him, he has to guide his unwilling soldiers through tunnels that are frequently filled with poisonous gas and dead bodies left by their occupiers. There's a telling narration early on as we see these men walking among the devastation; it details what they truly desired in life—and it’s that very sense of normalcy that defines their bravery as they try to confront their heavily armed enemies. "Michal" (Vladsek Sheybal) stands out, being a musician who simply wants to play the piano, but each of his fellow soldiers has equally simple wishes – like taking a bath or having some hot soup—which are now as destroyed as the city above. Andrzel Wajda’s direction is tight and focused, with the cramped setting they move through, the constant sound of dirty water flowing, along with gunfire and explosions all adding to a feeling of danger as the group slowly decreases in number while heading toward what they hope will be safety—and daylight. It should feel like something unavoidable, and thankfully Wajda and writer Jerzy Stawinski don’t avoid that, nor do they try to soften it. It's a powerfully acted, bleak story from beginning to end, but also one about hope and the human spirit; there's some very dark humor and a real sense of revulsion as they struggle onward through the rubble and corpses to fight another day.

Source on TMDB