My Secret Terrius[5] (Korean: 내 뒤에 테리우스; RR: Nae Dwie Teriuseu) is a 2018 South Korean television series starring So Ji-sub, Jung In-sun, Son Ho-jun and Im Se-mi.

It was aired on MBC from September 27 to November 15, 2018 on Wednesdays and Thursdays at 21:55 (KST).

Along with her neighbour Kim Bon (So Ji-sub), who was an NIS agent, they discover the truth behind her husband's involvement in a huge conspiracy.

And they succeeded in their plans Kingcastle is the housing complex where both Kim Bon and Go Ae-rin live.

A closely bound community, it has a Kingcastle Information System (KIS).