That is the title of a song, composed by Gabriel Fauré in 1878. You can search YouTube for a recording of it. I copy the translation in English:
Drowsing spellbound with the vision of you
I dreamt of happiness, burning mirage,
Your eyes were gentler, your voice was pure and sonorous
You shone like the dawn-lit sky
You called me and I left the earth
To flee with you toward the light
For us the heavens opened up their clouds
To reveal unknown splendour, glimpses of divine light...
Alas, alas, sad awakening from these dreams
I call out to you, oh night, give me back your lies
Come back, come back, radiant one
Come back mysterious night.
I thought it singularly appropriate for the deeply tragic tale of Brian and Christine Thomas. They were on holiday in West Wales in July 2008 and had parked their campervan on a site near the village of Aberporth. Late in the evening, the campsite was invaded by local youths in cars, who sped around the site, with screeching tyres and brakes. The couple moved to another part of the campsite to be rid of the nuisance.
It was after half past three in the morning, when Brian heard someone coming into the campervan. He jumped out of bed and commenced to struggle with one of the boyracers, in order to get him out.
Except, it wasn't a boyracer. Brian awoke from a nightmare, to find he had been struggling with his wife and had strangled her. He rang the emergency services to tell them. He was committed for trial on a charge of murder. Medical evidence revealed that Mr Thomas was suffering from a sleep disorder, which meant that it was impossible to distinguish between dreams and reality. As a result, he was acquitted on the grounds of diminished responsibility. The couple had known each other for 40 years.