In the Castle season 1 finale, "A Death in the Family" Kate Beckett is devastated when Castle does the one thing she asked him not to do, look into her mother's murder.

Just when Beckett finds the courage to take a chance on Rick in "A Deadly Game" she finds out she's too late. Castle has already made plans for the summer with ex-wife Gina.

Talk about a "Knockout" punch. In the Castle season 3 finale, Kate Beckett is shot by a sniper at Capt. Montgomery's funeral. All Castle can do is hold her and tell her he loves her.

After 4 seasons, Kate showed up at Castle's door to tell him exactly what she wanted. The kiss up against the door in "Always" left shipper hearts aflutter for the entire summer.

Just when it seemed that their entire relationship was on the line, Rick Castle stepped up, got down on one knee and asked Kate Beckett to marry him in Castle season 5 finale "

Just when Kate Beckett thought she was getting the beautiful wedding she deserved, she was called to see Castle's car in flames on the side of the road in season 6 "For Better or Worse"