Grey's Anatomy continues to show us that neither medicine nor relationships can be defined in black and white. Tensions at Grey Sloan Memorial rise as Owen and Teddy attempt to take the next step in their engagement. Bailey wants to hire new doctors. Richard is reenergised as he takes teaching to a new level at the hospital. Seattle's favourite redhead is back.

Levi faces a loss. An explosion rocks Seattle. Jo, Link and Amelia each find themselves at a crossroads. And as Meredith struggles with major decisions, she realises the end of an era is easier said than done. Watch as one of the great television shows of our time celebrates its 18th season with a history-making season finale 400th episode.