The anniversary of a Halloween killing spree at the Mish has Maggie seeing dead people and Frank seeing Shelly in a new light after she comes to his costumed aid in the ER. Meanwhile, a pregnant woman's misdiagnosis leads to a battle between Quinn and the chief of obstetrics over Kellerman's quick---and correct---decision to operate; and Dalgety gets in over his head helping a junkie bid make peace with her late love.