Hélène Barizet, a brilliant conductor with unorthodox methods, is back in Paris after twenty years to take over as head of the Philharmonia, a national orchestra.

A flood in the auditorium threatens the future of the orchestra. The director seeks help from Rafael Crozes, a wealthy patron with a scandalous past, but he is unaware that Crozes and Hélène are connected by a passion as destructive as it is intense.

The mysterious death of a musician hits everyone like a bombshell. Hélène is overcome with doubt, as she had had a violent dispute with the oboist just before his death. The director—who had been the musician’s secret lover—fears she is responsible.

When Hélène collapses during a concert, the director seizes the chance to replace her. But the musicians threaten to strike and demand her return. Meanwhile, Crozes coerces Hélène into moving in with him, or else he’ll pull all his financing.

Hélène returns to the podium, set on taking down whoever is trying to destroy the orchestra. Listening to her musicians play, where once she heard only admiration, she now discerns a note of hatred. Shaken and upset, she blames the wrong person.

Hélène finds a core of support within the orchestra that gives her the strength to face her demons. With the final concert approaching, she is eager to deliver a genius performance but realizes she must also accept the madness that comes with it.