The plot revolves around Niko Grimsby (played by Will Ferrell), a successful professional footballer living in London. He hasn't spoken to his brother Grimsby (played by Mark Wahlberg) for 30 years after their father disowned Niko for his career choice. However, when Grimsby appears at Niko's doorstep, claiming to have been kicked out of a sink or swim school due to his methods being deemed too old-fashioned, Niko reluctantly agrees to let him stay.