Canadian Stana Katic plays Det. Kate Beckett on Castle.

Tonight we'll find out more about Det. Kate Beckett's traumatic past in the season finale of Castle (A, ABC).

"The reason she became a detective was because she had a personal tragedy in her family," said Canadian Stana Katic, who plays Kate.

"She was probably on the road of any typical Manhattan girl, going to university and enjoying life. But then this came in and threw her for a loop and put her into the New York Police Department in a quest for justice, not just for her family but for other tragedies that she sees and empathises with."

Katic, who grew up in the Toronto area, stars alongside another Canadian, Edmonton's Nathan Fillion, in Castle. While nothing has been confirmed yet by ABC, the series -- which is kind of two-thirds drama, one-third light comedy -- is a good bet to return for a second season.