Paris, Christmas Eve, a freezing attic. Rodolfo and his bohemian friends burn the poet's manuscripts to keep warm. A knock at the door: it is Mimì, the neighbour, asking to light her candle. The candle goes out again — perhaps not by accident. In the darkness their hands meet. 'Che gelida manina' sings Rodolfo. They fall in love within five minutes.

Christmas night at Café Momus: merriment, wine, Musetta driving Marcello wild. But winter deepens. Rodolfo and Mimì quarrel, separate. Rodolfo confesses the truth to Marcello: he left Mimì because she is ill and he is too poor to care for her. Poverty destroys love — not jealousy, not betrayal.

Months later, in the same attic. Rodolfo and Marcello pretend cheerfulness but think of their lost loves. Musetta bursts in: Mimì is outside, she can no longer climb the stairs. They bring her in. Mimì is a shadow of herself. But she is at peace — she has returned to where she was happy. The friends go out to find medicine and a muff to warm her hands. They are left alone. Mimì falls asleep. Rodolfo watches her smile, thinks she is better. Marcello returns. Musetta weeps. Rodolfo understands everything.