The play unfolds in Bulgaria in 1885, towards the end of the Serbo-Bulgarian War. Raina Petkoff and her mother Catherine have received news that Raina’s fiancé Sergius led a victorious cavalry charge against Serbian forces. Louka, the household maid, enters to announce that the windows must be locked, as fleeing Serbian troops are being hunted down in the streets. Later that night a Serbian officer climbs the drainpipe outside Raina’s balcony and breaks into her room. Bulgarian soldiers arrive, asking to inspect the room, and Raina, overwhelmed by a moment of compassion, hides the enemy soldier behind her curtains. Louka is the only one who sees through the deception, but she only smirks and leaves in silence.
Once safe, the soldier comes out from hiding and explains he is a Swiss mercenary for the Serbian army. He admits to Raina that he does not carry cartridges for his gun, only chocolates, as these are more practical for a starving soldier. Thinking him childish, Raina offers the soldier some chocolate creams, which he devours hungrily. He explains that the cavalry charge led by Raina’s fiancé Sergius was only successful as a result of dumb luck. Angered, Raina finally demands he leave, yet the Swiss mercenary claims to be too exhausted to move. Feeling pity, Raina agrees to shelter him and runs to find her mother. When the two women return, the chocolate cream soldier, as Raina calls him, has fallen asleep in her bed.