Brothers Aaron (Chris Rock) and Ryan (Martin Lawrence) are attending their father's funeral, but with hardworking Aaron envious of his free-wheeling sibling's writing career, condolences are in short supply. A mix-up with some Valium, meanwhile, has caused cousin Elaine (Zoe Saldana) to give her nervous boyfriend Oscar (James Marsden) a powerful hallucinogenic.
With the rest of the dysfunctional Barnes clan congregating, the day looks set to run anything but smoothly, and before long Oscar is wreaking havoc. But the biggest upset is yet to come, when an unexpected visitor (Peter Dinklage) arrives with a shocking revelation.