In a summer full of sequels, who would have thought the best one would show up in September? Well, as the saying goes, "save the best for last," and writer/ director Robert Rodriguez certainly has with the final installment of the El Mariachi series: Once Upon A Time in Mexico. Rodriguez explains that Once Upon A Time... is actually "Part 4" of the Mariachi story with a "Part 3" that is merely alluded to in flashbacks. So it's not really necessary to have seen El Mariachi or Desperado to understand and appreciate the events of Once Upon a Time in Mexico.

El Mariachi has been hired by a CIA agent named Sands to kill a man named Marquez. Marquez is planning to overthrow the president and also happens to have killed El Mariachi's wife and daughter in "Part 3." In addition, Marquez is working for a cartel leader named Barillo who, after a successful career as a drug lord, wants to dispose of the president and then slip quietly into retirement leaving Marquez in power. Also involved: a disgruntled Federale agent, an ex-FBI agent, an ex-con, a tiny dog, a brave little boy and Enrique Iglesias.

Got all that?

Not to worry, Rodriguez does a fair job of keeping everything sorted out for you. But don't get up and go to the bathroom as you are virtually guaranteed to miss something in this mil-a-minute plot.

You can just feel that everyone involved in Once Upon A Time... had a lot of fun making this film and really cared about making it fun for the audience as well. In a flashback scene, Carolina and El Mariachi must escape down the side of a five-story building while chained together at the wrists. Not only do our heroes take turns swinging, dropping, and dangling each other down from floor to floor, Hayak and Banderas do their own stunts. The film is also full of great visual gags like a bribe presented in a Clash of the Titans lunch box and a C.I.A. agent wearing a "Cleavage Inspection Agency" t-shirt to disguise himself as a tourist.

Returning from the previous films are Rodriguez regulars: Danny Trejo, Cheech Marin (as different characters) and, of course, Antonio Banderas. This time around, Banderas' Mariachi is a little different, a bit more stoic. The Mariachi's heart is heavy with the loss of his dead love, Carolina, but it doesn't deter him from loading up his guitar with bullets and blasting away a room full of bad guys. New to the story and with as much screen time as Banderas is Johnny Depp as C.I.A. agent Sands. Depp is a real show-stealer in this film with a hilarious performance that registers somewhere between Ed Wood and the pirate Jack Sparrow.

Once Upon a Time in Mexico was "shot, chopped and scored," not to mention written and directed by Robert Rodriguez. It's his best film to date, and I say "to date" because this guy gets better with every movie he makes and what's more: he does it without a perpetually expanding budget. Once Upon a Time in Mexico only cost 30 million to make (compared to an average 120 million price tag for the other summer action movies). How does he do it? Because he knows how to make the most of simple tricks that cost next-to-nothing: like creative editing! When El Mariachi reloads his rifle, he does it in exactly one point five seconds. You see the barrel drop, a flash of a hand inserting a slug, a flash of the barrel clicking back into place and then BLAM, he fires. This "action short-hand" makes El Marachi seem like the fastest gunslinger on the face of the earth, no special effects required. Another simple but effective element: Big guns and big bullets. El Mariachi and his gang get their hands on some "super bullets" that literally blow people across the room. So simple! So cool to watch! It's way better than some idiot with a machine gun or some overused vinyl-clad, slow-motion, quasi-kung fu move.

Once Upon a Time in Mexico is an entertaining and fun film from start to finish; it's a great ride. Highly recommended.

-Megan A. Denny