Polish football is renowned for its passion, popularity, and tightly-fought title contests, but also for the hooliganism and clashes between supporters which have mired the sport over the years.

No team has a worse reputation in this regard than Wisła Kraków, whose rivalry with neighbouring KS Cracovia is widely regarded to be the most dangerous in all of world football.

In this documentary, HITC Sevens takes a look at the history of Wisla Krakow, their infamous ultras - the Wisla Sharks, how they took control of the club, and how Jakub Błaszczykowski has returned to try and save them.