THE 90-MINUTE SEASON FINALE IS PACKED WITH MURDER, BETRAYAL AND AN UNFORGETTABLE GRADUATION DAY FOR ALL - Clark (Tom Welling) begins to piece together the reason he was sent to Earth after he has a nightmare that something horrible is going to happen to Smallville and heads to the cave to seek answers from Jor-El. His biological father tells him he must reunite the three crystals immediately or a disaster of epic proportions will befall the planet and even Clark won't be able to stop it. Meanwhile, Lex (Michael Rosenbaum) helps Lana (Kristin Kreuk) escape Smallville after the death of Genevieve Teague the takes shocking action to get one of the crystals away from Lionel (John Glover). Realizing they are connected to Clark, Chloe (Allison Mack) tries to stop Lex from discovering the truth about the crystals. Jason (Jensen Ackles) takes Jonathan (John Schneider) and Martha (Annette O'Toole) hostage and threatens to kill Martha unless Jonathan tells him where Clark hid the crystals. Greg Beeman directed the episode written by Todd Slavkin & Darren Swimmer (#2T522)