In theaters

MEMENTO. 113 minutes, R, written and directed by Christopher Nolan, based on the short story by Jonathan Nolan.

Christopher Nolan’s neo-noir thriller, “Memento,” has a shocking beginning, which comes at the end, and an equally gripping ending, which comes at the beginning.

If this sounds at all peculiar, there’s good reason: “Memento,” much like Harold Pinter’s 1983 film “Betrayal,” tells its story backward.

Well, somewhat backward. Without giving too much away, what’s closer to what occurs on screen is the shattering of chronological time in favor of a gimmick that works – so long as one doesn’t study its mechanics too closely.

The film stars Guy Pearce (“L.A. Confidential”) as Leonard Shelby, a man with a shock of bleached-blond hair and a face filled with bloody scratches whose short-term memory was destroyed after he witnessed the brutal rape and murder of his wife.

Now literally living in the moment while being haunted by memories of the past, Leonard is desperately trying to find the man who murdered his wife so he can have his vengeance. But since the passing of only a few minutes can literally wipe Leonard’s short-term memory clean, keeping track of his investigation and finding the murderer proves extremely difficult for him to do.

To help him make sense of his progress, Leonard tattoos his body with facts of the case while also maintaining a diary of Polaroids, most of which contain head shots of those people he suspects will either help him – or harm him. Indeed, scrawled beneath each photo are clues that are useful to Leonard but which might, we suspect, not tell the complete truth of who these people are.

Disclosing too much of the plot would kill the often challenging experience of putting its many pieces together; much of the film’s appeal rests in the fact that audiences must do as much work as Leonard to root out the murderer. So we’ll leave it at this: Nolan, working from a short story by his brother, Jonathan, has created a thriller of great energy and style whose success depends on our continuing state of confusion.

Just as he should be, the director is one step ahead of everyone here, but by film’s end, where he reveals his stunning beginning, Nolan unfortunately finds himself doing too much explaining to tie up the loose ends he’s gathered along the way. To be sure, the many twists and turns that pepper the dense final moments of “Memento” seem more the product of contrivance and less a natural extension of all that came before.

Grade: B+.

On Video and DVD

BEST IN SHOW. 90 minutes, PG-13, directed by Christopher Guest, written by Guest and Eugene Levy.

In its cruel, yet all-too-truthful observations, Christopher Guest’s hilarious mocumentary, “Best in Show,” suggests that some dog owners, particularly those who shamelessly peddle their pooches in elaborate dog shows, are no better than some beauty pageant mothers – cloying, hysterical, insecure louts who will do anything to make certain their little Fifi or Fido take home the trophy for Best in Show.

The film is scathing, biting, a sharp, bitchy satire that keeps getting meaner and meaner – not to mention funnier and funnier – as the festivities it swirls around gradually snowball into doggy hell.

I loved this film. Just as Guest did so superbly in his 1997 movie, “Waiting for Guffman,” his latest consistently and happily takes an ax to – and skewers – the worst aspects of human nature.

The dialogue, most of which was improvised by the cast, is a triumph of coy understatement; throughout, the characters unwittingly reveal themselves with some terrific one-liners. Indeed, whether you come to hate or love these people for their mother lode of shortcomings, you’ll almost certainly recognize at least one of them as an amplified version of someone you know.

The film, which builds to the fictional Mayflower Dog Show in Pittsburgh (think New York’s Westminster), follows the trials and tribulations of several dogs and their owners, most of whom are as neurotic as a lone Chihuahua in a pen filled with pit bulls.

We meet Gerry Flek (Eugene Levy), his loose wife Cookie (Catherine O’Hara) and their Norwich terrier, Winky; Harlan Pepper (Guest) and his slobbering bloodhound; Stefan Vanderhoff (Michael McKean), his partner, Scott (John Michael Higgins), and their precious Shih Tzu; the saucy Sherri Ann Ward (Jennifer Coolidge), her handler, Christy Cummings (Jane Lynch), and their standard poodle; and finally the impossible Swans (Parker Posey and Michael Hitchcock), who are so high-strung, they’ve taken their Weimaraner to counseling ever since the dog saw them having sex.

With Fred Willard in a brilliant spoof as a fumbling television sports commentator who freely speaks his mindless mind, what ensues in “Best in Show” is so funny, even cats might agree – this film is something to chow, chow, chow about.

Christopher Smith is the Bangor Daily News film critic. His reviews appear Mondays in Style, Thursdays in the scene, Tuesdays on “NEWS CENTER at 5” and Thursdays on “NEWS CENTER at 5:30” on WLBZ-2 and WCSH-6. He can be reached at BDNFilm1@aol.com.

THE VIDEO CORNER

Renting a video? NEWS film critic Christopher Smith can help. Below are his grades of recent releases in video stores.

Antitrust ? D

Best in Show ? A

Pay it Forward ? C

Duets ? D

Quills ? B

What Women Want ? B

Yi Yi ? A

All the Pretty Horses ? C-

Miss Congeniality ? B

The Emperor’s New

Groove ? A-