Husband/chef replies, "As though the blood just stopped."

And since the lamb is still alive in his box, things are going to get messy. Hunter Gatherers, Peter Sinn Nachtrieb's funny, nasty farce about primal instincts, opens Theatre Exile's season in high style.

Richard, played by Ross Beschler, is a yuppified Tarzan - a foodie with a sex drive so opportunistic that anybody and any gender will do.

His tyrannized wife - "being good is who I am" - Pam (Amanda Schoonover) is eager to please, the saluting "Skipper" to Richard's "Boat." She will come to see just how stupid and meaningless these marital nicknames are.

They are preparing the lamb dinner for their yearly reunion with two old school friends, another mismatched couple: Wendy (Sarah Sanford), who is desperate to have a baby and consequently contemptuous of her impotent physician husband, and Tom (Matt Pfeiffer), a weakling who has been tormented and bested by Richard since they were boys. His sexual ineptitude and Wendy's rapaciousness - "thick toxins of lust" - set up the plot.

Act 2 begins with the question: "You lose faith in your friends, what's left?" And the answer arrives, loud and clear: "Revenge."

It's not just the revenge of a cuckolded husband or the revenge of the repressed saintly wife, but of human nature itself. Strip away the thin top layer of civilization and what you find, growling and slavering right under the surface, is the Inner Beast.

Deborah Block, who directs this wildly physical and violent show, has a cast of four actors who have perfect comic timing and who seem unafraid of the hilariously fearsome challenges of the script (hats off to John Bellomo, fight director).

Their faces are mobile and expressive, managing to rescue with subtlety what might otherwise be a one-joke play. And there is a nifty coup de theatre (set designed by Meghan Jones) as the final treat.

Hunter Gatherers

Presented by Theatre Exile at the Adrienne Theatre, 2030 Sansom St., through Nov. 22. Tickets: $15-$30. Information: 215-218-4022 or www.theatreexile.org.