BUTCH BOWERS: In Insomnia, Ralph remembers his mother telling him, "make sure that old thief Butch Bowers doesn't put a lot of rotten potatoes at the bottom of the peck basket."
Butch Bowers was Henry Bower's father in It. Henry killed him.
MIKE HANLON: The Derry Library librarian in Insomnia.
One of the Losers in It.
BEN HANSCOM: Referred to in Insomnia as the "one-time Derry resident" who designed the Derry Civic Center, a replacement for the one destroyed in the flood of '85.
One of the Losers in It.
OFFICER ALOYSIUS NELL: Ralph remembers Mr. Nell, the one adult in Derry who knew the children's secret streets and hideaways.
The officer who discovered the dam the losers built in It.
THE BLACK SPOT: Doc Mulhare said in Insomnia, "Things have a way of happening here. Remember the fire at the Black Spot?"
The Black Spot's story is told in detail in It.
DERRY PUBLIC LIBRARY: Where Ralph researches his insomnia and is stabbed by Charlie Pickering in Insomnia.
A favorite place of Ben Hanscom, and Mike Hanlon's later place of employment in It.
DERRY STANDPIPE: Ralph sits on a bench "not far from the place where the Derry Standpipe had stood until 1985, when the big storm had come along and knocked it down."
In It, the Standpipe was thought to be a dangerous place.
JUNIPER HILL ASYLUM: In Insomnia, Charlie Pickering spent six months in the place.
In It, Henry Bowers spent a little more time.
SECONDHAND ROSE, SECONDHAND CLOTHES: A jumbled junkatorium at the bottom of Up-Mile-Hill in both books.
THE ALLADIN THEATER, THE BARRENS, THE HOBO JUNGLE: Ralph thinks of these places as parts of Derry that belonged to the secret world of children.
They all place a major part in It.
Streets common to both books: MAIN, NEIBOLT, WITCHAM, UP-MILE-HILL.
KENDUSKEAG STREAM and the PENOBSCOT RIVER are mentioned in both books
DEADLIGHTS: While struggling with the Crimson King in Insomnia, Ralph catches a glimpse through the unimaginable levels of existence above him, full of lights, colors, glows and knew that "if he looked too long into those [deadlights] that death would not be the worst thing that could happen to him, but the best."
The deadlights in It were IT's eyes. You didn't want to look into them too long.
DEATH OF ADRIAN MELLON: Ralph thought that Derry had an extra dimension of ugliness and remembered when three boys had thrown Adrian Melon off the bridge into the Kenduskeag.
Adrian's death is fully detailed in It.
PAUL BUNYON STATUE: In Insomnia, Joe Wyzer drives past the "hideous plastic statue of Paul Bunyan."
This is the same statue that came to life one day and attacked Richie Tozier in It.
THE STORM of '85, THE FLOOD of '85: This storm is mentioned several times in Insomnia.
They're talking about the ruckus that occurred when the Losers fought IT for the second time and succeeded in destroying it.
SHAPE-CHANGING: The Crimson King tells Ralph in Insomnia, "You may not know it, but shape-changing is a time-honored custom in Derry."
A pretty obvious reference to the many shapes of Pennywise the clown, IT.