On Thin Ice (Russian: По тонкому льду, romanized: Po tonkomu ldu) is a 1966 Soviet spy film directed by Damir Vyatich-Berezhnykh, based on Georgiy Bryantsev's 1961 book, which provided the first authoritative public description of counterintelligence group GUKR (SMERSH).

[1][2][3] The film tells the story of two NKVD agents who fight foreign spies in the Oryol Oblast before and during the Second World War.

In 1939, the trio begins tracking Colonel Dunkel, a German intelligence operative, but he manages to escape.

With the outbreak of war, the agents are tasked with locating an enemy intelligence center and disrupting its operations.

Their mission brings them face-to-face with Colonel Dunkel once again, ultimately resulting in his capture and successful transfer across the front lines.