Svět pod hlavou (English: World under Head, also known as Shadow of the Ferns) is a Czech mystery television series.

Elite policeman Filip Marvan is forced to steal evidence to protect his brother who owes money to a mob.

Plachý eventually turns out to be the only cop "with character" in an almost spineless department of party members and meritorious workers, who often put the desired conclusions above the actual investigation.

Marvan gets to know his commander Major Špalek, slightly more or less incomprehensible Slávek Brousek or party cadre Klement Kratěna.

Relatively soon he gets in touch with his parents - mother who is daughter of the director in the cultural center and father who is a member of problematic subculture called "máničky".

Filip then crosses state border his guide to the "world under his head" Martin Plachý is seriously shot but during the attempt.

He also discovers that the one who helped him the most - Martin Plachý - was a real person and was innocently executed for Slávek's murder and "espionage".