"In dreams I walk with you
In dreams I talk to you.
In dreams you're mine
All the time
In dreams, only in dreams..."

Henry (Jack Nance) and a familiar floor in Eraserhead...

Roy Orbison's haunting "In Dreams" played a major role in Lynch's Blue Velvet, and the dreams that  flow through Twin Peaks (and Twin Peaks) are as much a part of the town's geography as the river.  Not only does Agent Cooper rely, quite matter-of-factly, on dreams and visions to help him crack the case, dream-agents appear specifically to tell him things, and to warn him of things to come.  In Twin Peaks: Fire Walk With Me, Agent Cooper appears in Laura's dream to warn her not to take the ring that once belonged to Theresa Banks -- and this is before Cooper has ever physically visited Twin Peaks or had any conscious knowledge of Laura Palmer.   

Laura's mother (Grace Zabriskie) is also haunted by visions -- of a strange man lurking in her house, behind the furniture.  He first appears to her in a kind of memory/vision, crouching at the foot of Laura's bed.  His name, as it turns out, is Bob...