A cascade reaction is a phenomenon which can occur in a star due to an imbalance in fusion reactants in its core. Such a phenomenon was present in the Gamma Quadrant star Trialus. The cascade reaction in the star resulted in a dimensional shift in the star's only planet, Meridian. This caused Meridian to undergo periodic transitions to a dimension which intersected our own, where the inhabitants existed in a non-corporeal state. (DS9: "Meridian")