Judging from this synopsis, the film is a typically French affair, dealing with adultery, madness and doomed love...
"A struggling, middle aged entertainment journalist falls for a 20 year old psychotic pyromaniac. He meets the young woman when he goes to interview his ex-wife, a prominent actress in a mental institution. After the interview, the young woman sets fire to the institution after she overhears the conversation. Escaping to the woods, the reporter finds her and falls in love. The two decide to live in the forest in a lean-to, and they start their affair of burning passion while she continues her passionate burning. Soon the police arrive to take the disturbed woman away. The incident leaves the man on the verge of suicide out of loss and longing for his new love."
Now take a look at the back cover, and you see the immortal tag line "direction musical et arrangements: Jean-Claude Vannier" an almost certain stamp of quality. And in this instance, I'm pleased to say that J-C does not disappoint.
Don't know about you, but, for me, it brings to mind a more twisted version of the Lullaby from Rosemary's Baby sung breathlessly by a Lolita-esque Jane Birkin/Léonie impersonator.