In the dead of night
Definition 1 of 1
Pro Tip 1/3Quiet Intensity
Highlights something happening unexpectedly and quietly, creating a feeling of intensity or secrecy. 
He received a mysterious call in the dead of night.
Pro Tip 2/3Dark Ambience
Used to set the scene for eerie, suspenseful, or hidden activities occurring at night. 
Whispers were heard in the dead of night.
Pro Tip 3/3Emotive Language
Evokes emotions or suspense, often in storytelling or setting a narrative scene. 
In the dead of night, the ghostly figure appeared.