William Sleator

An American Speculative Fiction writer who mainly targets his books towards young adults. The format that many of his stories take run along the lines of "What if (insert abnormal phenomenon) existed and a kid/a bunch of kids stumble upon it".

His works include:

 * Among The Dolls
 * The Angry Moon
 * The Beasties
 * Blackbriar
 * Boltzmon
 * The Boy Who Couldn't Die: A teenager responds to an ad in a newspaper purporting a way to live forever. He becomes a voodoo zombie.
 * The Boy Who Reversed Himself: A girl meets a boy who has the ability to travel in the fourth dimension.
 * The Cupcake
 * Dangerous Wishes
 * The Duplicate: A boy finds an alien device that clones himself.
 * The Elevator
 * Fingers
 * The Green Futures Of Tycho
 * Hell Phone
 * House of Stairs: Five children are trapped in a house filled with endless staircases and are forced to play mind games with a machine for sustinance.
 * Interstellar Pig
 * Parasite Pig: The sequel.
 * Into The Dream
 * The Last Universe
 * Marco's Millions
 * The Boxes: A girl discovers some strange creatures in a box that have the ability to distort a person's perception of time.
 * Monster
 * The Night The Heads Came
 * Oddballs
 * Once, Said Darlene
 * Others See Us
 * Rewind: A boy dies and his life is rewound back to a few weeks before his death in an attempt to rectify the situation.
 * Run
 * Singularity: A couple of twins discover a shack that has a strange Time Dilation effect due to its relationship to a black hole.
 * The Spirit House
 * Strange Attractors
 * Test
 * That's Silly

Tropes associated with William Sleator:

 * Applied Phlebotinum
 * Magic A Is Magic A
 * What If