Küstenwache is a German television series that tells the fictionalized adventures of a unit of Federal Coast Guard officers off the German coast of the Baltic Sea.

Philipp Gabert and his best friend, Dr. Nicolas Amberg, are hiking in the mountains. Suddenly, Philipp suffers a strange attack of weakness and loses consciousness. Nicolas is only just able to prevent his fall. But the friendship between the two men is burdened by a problem: Nicolas is secretly in love with Philipp's wife Julia - and feels like a traitor. When the men set off on another mountain tour, only one of them returns. Was it an accident or murder?