Fifteen-year-old Greta Kovachi travels with her brilliant father to a laboratory habitat in a submarine on the bottom of the Pacific Ocean. Her father has created the first man-made black hole to prove that all matter in the universe is made up of infinitesimal particles of time. Greta was looking forward to this adventure, but she gets more than she bargained for. What was supposed to be a trip of a few days turns into a nightmare when an accident with the black hole spins them billions of years into the future, trapping her dad along with the other scientists in a particle of time. Three other kids live on the habitat, and, calling themselves the Aquanauts, they band together with Greta to travel through layers of time in a frantic attempt to save their parents and themselves from being locked under the sea for eternity.