Primetime television's most riveting hour hits new heights as secrets of the past come to light and critical choices shape the future. Relationships are in turmoil as things between Callie and Arizon cool -- and Owen and Amelia's romance ignites. April and Jackson face a heartbreaking tragedy. Meanwhile, Meredith makes a stunning family discovery as opportunities pull Derek further away. And Maggie's shocking announcement proves that blood is thicker than water.