Puccini's 'La Boheme' is based on Henri Murger's novel 'Scènes de la vie de bohème', which draws it's inspiration from the Bohemian lifestyle which was somewhat in vogue in Paris at the time. This Libretto by Giuseppe Giacosa and Luigi Illica runs as follows:
Rodolfo’s neighbour in his garret Mimi knocks at the door, saying her candle has gone out on the stairs. Rodolfo and Mimi sit in the dark talking and fall for each other. They go to meet Rodolfo’s friends. While there, Marcello's former lover Musetta arrives with her new husband Alcindoro, but, distracting him, falls into Marcello's arms. Some time later Mimì pours out her distress to Marcello over Rodolfo's incessant jealousy, Rodolfo is actually concerned about Mimi’s poor health and wants to part with her. On realising this, the two decide to stay together until spring, Marcello and Musetta meanwhile part when she is unfaithful.
Some months later, Rodolfo, Marcello and friends are amusing themselves in the garret when Musetta bursts in, saying Mimi is downstairs and has begged to be taken to her lover to die. She dies almost happily, recalling their early love.