Complex sentence: Rita, afraid of being recaptured by Loveless, grabs one of Gordon's rigged pool balls., accidently releasing sleeping gas that knocks out West (whom she thought was Loveless), Gordon and herself.
Split into simpler sentences: Rita, afraid of being recaptured by Loveless, grabs one of Gordon's rigged pool balls. She releases sleeping gas, knocking out West (whom she thought was Loveless), Gordon and herself.