“Underdog” is a story inspired by true events, transformed into a script by Mariusz Kuczewski. Borys “Kosa” Kosiński (Eryk Lubos) is an MMA fighter at his peak. In the most important fight with his biggest rival, Deni Takaev (Mamed Khalidov), he makes a mistake that costs him his career and loses everything.
“Underdog” tells a story about human weakness and strength, about despair overcome by budding love, about fighting with fate and rising after a fall, about sacrifice, family and friendship.