HBO has released the first teaser for its upcoming film 7 Days in Hell, a Christopher Guest-esque mockumentary about an epic (but fictional) seven-day tennis match.

Andy Samberg and Kit Harington play the men who left it all on the court—mulletted troublemaker Aaron Williams (Samberg) and dim-witted prodigy Charles Poole (Harington). The film promises a host of celebrity cameos, including Serena Williams and Soledad O’Brien, but the true star of this teaser might be Will Forte’s tennis racket blazer. Unless it’s Harington’s man bun. (It’s the man bun.)