Keith David

When the annual bicycle messenger race takes place in Seattle, the hospital emergency room fills with an assortment of injuries, causing the interns to compete for the most severe cases. Meanwhile, Derek and Burke compete for the chief resident position, and while Derek continues to pursue Meredith romantically, a patient flirts with George.

After seeing Marvin blissfully enter retirement, Grandma Huang decides it's her turn to retire from something; when Louis fails to celebrate her as she wanted, it will take a visit from Hurricane Gene -- and maybe a hot tub -- to make things right.

Dre realises he needs to intervene when Pops starts gambling and partying to mask his heartbreak; Bow pawns school drop-off onto Junior so that she can avoid an annoying parent.

After Frankie banned Greendale's yearly paintball game, the game has gone underground and is threatening to ruin Frankie's "Cleaner Greendale" gala. At Frankie's request, it is now up to Jeff and the crew to stop the paintball game and expose "Silverballs", an unknown player who shoots silver paintballs.

Garrett gets engaged in Jeff's classroom and Jeff and the crew are invited to the wedding. After arriving late to the ceremony, making a scene at the reception, and being told off by the groom's mother, the crew splits off and tries to be the best wedding guests ever.