Vagabond

Cha Dal Gun becomes an awakened tiger in the face of his nephew’s death in a mysterious plane crash. As an orphan himself, he had raised his nephew singlehandedly in place of his brother who had passed on. Triggered by the large-scale cover-up of the incident, he sets off on a journey to discover the truth.
Go Hae Ri is the eldest daughter of a marine who had died during an operation. She has always wanted to be a normal civil servant to support her family, but life had other plans and she ends up as a National Intelligence Service (NIS) agent.
Their lives intertwine as they discover a tangled web of corruption behind the plane crash.
(Source: The Swoon)