With the entire city ordered to take a personal day the team does their best to unwind and enjoy their leisure time. Without warning a mysterious explosion rips through the city killing and injuring unsuspecting citizens. Dr. Rodney McKay and Dr. Carson Beckett arrive on the scene to find Teyla critically injured by shrapnel from the explosion. Unable to find explosive residue, the only leads they have to go on are eyewitness accounts saying one of the base-scientists just suddenly exploded.