7 days in hell, andy samberg, kit harringtonAndy Samberg and Kit Harington may seem like an unlikely pair of people to play tennis stars, but when you find out they're headlining a mockumentary, it actually makes perfect sense.

The "Brooklyn Nine-Nine" and "Game of Thrones" actors are front and center in "7 Days in Hell," which tells the (fake) story of tennis rivals Aaron Williams and Charles Poole, who become part of the longest -- and most grueling -- match in the sport's history. The mockumentary not only features footage from the game itself, but interviews and behind-the-scenes looks at both players, as well as a slew of celebrity cameos, including everyone from Will Forte and Mary Steenburgen to Serena Williams and John McEnroe, among many others.

Samberg sports some ridiculous hair (a shout-out to the pre-bald stylings of Andre Agassi) and increasingly more severe injuries as the match progresses, while Harington spins his racquet and dives to return serves. It's all so over-the-top, and yet so utterly convincing, striking a deadpan tone that suggests the film takes itself completely seriously, even when viewers are giggling over the ridiculous antics on display.

Check out the trailer below, and get ready to fall in love (sorry).

"7 Days in Hell" debuts on HBO on July 11.

Photo credit: YouTube