A major aspect in any work by Irish playwright, screenwriter and director Martin McDonagh is great gobs of pitch black humor.

Comedy so dark and yet so rich that it is nearly impossible to stop a laugh, a giggle, a guffaw from escaping.

Wit like a bar of chocolate that is 98% cacao, which means it is indeed an acquired taste but one that can be savored.

I use that allusion to chocolate for a reason because no matter how horrible the events in one of McDonagh’s works become—and they can get pretty dreadful—there also is a bit of sweetness somewhere to temper all that dreadfulness.

Sometimes you have to look closely for that sweetness, but it’s there, from the dysfunctional mother and daughter in his brilliant play The Beauty Queen of Leenane to the torturous—and torturing—soldier mourning the death of his best friend, who happens to be a cat, in the equally brilliant play The Lieutenant of Inishmore. At the heart of his fascinating and bleak play The Pillowman is a heartfelt relationship between two brothers.

In his second feature film as a screenwriter and director, McDonagh allows that bit of sweetness to seep into Seven Psychopaths courtesy of Bonny, the beautiful little shih tzu who is adored in the most profanity-riddled terms of endearment that owner Charlie Costello (Woody Harrelson) can muster.

Bonny is the only love of Charlie’s life and the little guy’s kidnapping pushes Charlie to brink of uncontrollable revenge and violence. Not that Charlie, clearly the main psychopath in all this, was all that clear-headed to begin with.

Before I go any further, I must say that while there is a lot of violence and blood in Seven Psychopaths, Bonny—who acts as the film’s moral center—is never harmed. If he were, I don’t know how I could have explained that to our little Houdini, the black and white fluff ball of love at left. Bonny is the tan and white dog.

Bonny is the latest target of a rag-tag gang of dognappers that include Billy (Sam Rockwell) and Hans (Christopher Walken). The pair kidnaps dogs and then returns them for the reward money. That’s all well and good until they take the wrong dog, the beloved Bonny. Somehow the hard-drinking screenwriter Marty (Colin Farrell) is drawn into the scheme.

The movie is called Seven Psychopaths for a reason and there are indeed seven. Some are real; others are figments of Marty’s imagination and part of the screenplay he can’t quite get off the second line of his legal pad.

A Buddhist psychopath who then becomes an Amish psychopath and finally a Quaker psychopath is a running gag throughout the movie.

McDonagh seems to be having a lot of fun with his many allusions to genre standbys of action films and crime dramas. His deranged wit mixes the sensibilities of Guy Ritchie and Quentin Tarantino with his own approach.

Those who appreciate Pulp Fiction, 2 Days in the Valley and Dexter may find much to like in Seven Psychopaths. A movie with the name Psychopath in its title and starring Walken and Harrelson almost seems redundant and both actors make the most of their roles. Harrelson—who is psychopath No. 3—is clearly the worst of the lot and his performance often borders on the clichéd, but that seems to be the point. Walken almost tamps down his usual crazy persona as he plays a loving husband whose wife is dying of cancer.

Grungy handsome Farrell again shows that he’s not just a pretty face but an insightful actor who can toss off witty one liners as well as show that there is a writer hiding behind Marty’s alcoholic haze.

I am beginning to think that Rockwell never plays a normal character, but that is fine. His out of control Billy, who has a lot of secrets, is one of his best psychopaths. And the bunny-cradling Tom Waits, as another psychopath, is searching the world for his true love who dumped him, breaking his heart but leaving him surrounded by rabbits.

Seven Psychopaths is not all dark humor. It also is a violent, bloody movie. Still, only one death—and, no, it is not an animal—is gratuitous and chilling and seems so unnecessary. At the same time, this scene reinforces that Seven Psychopaths is about some very dangerous people from whom no one is safe.

But Seven Psychopaths also is about the unconditional love of little Bonny...well, that, and McDonagh’s dark humor.

Seven Psychopaths rated R for strong violence, bloody images, pervasive language, sexuality, nudity and some drug use.. Running time: 110 minutes.

Photos: Top: Woody Harrelson and Christopher Walken in Seven Psychopaths; second photo: Colin Farrell, Christopher Walken, and Sam Rockwell; third photo: Bonny; fourth photo: Houdini Cogdill-Hirschman. Photos of Seven Psychopaths courtsey CBS Films.