While working in his basement, Quinn Mallory opens the gateway to parallel worlds. For a test run, Quinn invites co-worker Wade Welles and his teacher, Professor Arturo, along. Upon opening the vortex, Quinn uses too much power, which causes the vortex to suck them in along with Rembrandt "Crying Man" Brown, who happened to be driving by Quinn's house. The four arrive on a world that experienced an ecological disaster and will have to survive until the timer hits zero.

The Sliders arrive on a world just like their own, only time is moving at a rate of twelve years slower than normal. There, Quinn encounters his young double and tries to change an upcoming event in his life, despite the other Sliders' warnings.

Things don't look good for the Sliders when they slide to a world that's about to be eradicated by a rogue pulsar. Soon they discover that this world has been developing sliding technology and pool their resources with the U.S. government in a race to escape to a parallel Earth.

After three months and ten worlds of searching for Wade and Rembrandt, Quinn and Maggie finally reach Earth Prime, only to find it under Kromagg control. Quinn and Maggie manage to rescue Rembrandt from a Kromagg prison, but Quinn is captured and learns the shocking truth about his family.

The Sliders arrive in the middle of a rally, surprisingly being held in their honor. They learn they are the subjects of a religion called Slidology, founded by a man with psychic abilities. He has been following their adventures and warns that on their next slide, they will all die.