On the morning of their father's funeral, the family and friends of the deceased each arrive with his or her own roiling anxieties. Son Daniel (Matthew MacFadyen) knows he will have to face his flirty, blow-hard, famous-novelist brother Robert (Rupert Graves) who's just flown in from New York, not to mention the promises of a new life he's made to his wife Jane (Keely Hawes). Meanwhile, Daniel's cousin Martha (Daisy Donovan) and her dependable new fiancé Simon (Alan Tudyk) are desperate to make a good impression on Martha's uptight father - a plan that literally goes out the window when Simon accidentally ingests a designer drug en route to the service, leaving him prone to uncontrollable bouts of delirium and nudity in front of his potential in-laws.

Then comes the real shocker: a mysterious guest (Peter Dinklage) who threatens to unveil an earth-shattering family secret. As riotous mayhem and unfortunate mishaps ensue on every front, it is now up to the two brothers to hide the truth from their family and friends and figure out how to not only bury their dearly beloved, but the secret he's been keeping.