Christmas Eve, 1914: hunkered down in the trenches, British soldiers begin to hear something unusual — instead of exploding shells, strains of the carol “Stille Nacht” begin to cross No Man’s Land as German soldiers sing to mark the holiday. Soon after, soldiers began to lay down their weapons and cross into No Man’s Land. They exchanged gifts of food and tobacco, sang together, and even buried each other’s dead. Styled as a radio musical drama, All Is Calm tells the story of the Christmas Truce through the words of those who were there, using text from “letters, journals, official war documents, poetry [and] grave stone inscriptions” among its sources. The Playhouse’s production features San Antonio’s all-male a capella group The Marcsmen, and for anyone looking for a double dose of holiday cheer, a special double feature of All Is Calm and A Marcsmen Christmas will run on December 17.