The boys at Pixar Entertainment did it again. In their fourth installment, after the Toy Story franchise and A Bug’s Life, executive producer John Lasseter and company have made yet another highly enjoyable film with Monsters, Inc.

Just as Pixar’s previous efforts have examined the fictional lives of either toys or bugs – here, the central characters are monsters, while again keeping animated human characters to a minimum.

Taking the premise of a parallel world where monsters live and thrive for energy sources just like humans do on earth, the film realistically creates Monstropolis, a functioning city that feeds off the screams collected by scared children. So yes, there actually are monsters in the closet, and these monsters are some of the most entertaining creatures to grace the silver screen this year.

The screams are collected into canisters attached to the other side of each child’s closet door, which serves as a gateway to the human world.

In the scare factory, there is a core group of monsters that are otherwise friendly when not scaring the lights out of unsuspecting children. They all compete with each other but seem to always fall short of the quota set by the lovable, furry Sulley (voiced by John Goodman). Each monster has a trainer, and Sulley, as well as the audience, is lucky enough to be coached by Mike (the hilarious Billy Crystal).

Mike and Sulley coast through life as jolly as can be, with only the minor inconvenience of an energy shortage caused by the lack of screams from children who are not afraid of monsters the way they used to be.

The only thing to worry about in Monstropolis is letting children into the monster world. Apparently, a child’s touch or article of clothing can infect and ultimately destroy a monster. And wouldn’t you know it? The plot centers on Mike and Sulley’s dilemma of dealing with a child who crosses over accidentally.

While there is more to the story, to give away any of it would be a crime.

Of course, the animation is fabulous, but it’s nothing we haven’t seen before. The script is still top-notch with humorous lines for both adults and children. But the real treat here is the story and the fabulous jobs by Goodman, Crystal and Sulley’s archenemy monster, the always-animated Steve Buscemi. And while celebrity voices have always been the saving grace of most animated films, here it seems the members of this group do more to become the characters and at no point do the familiar voices distract from the poignant story of which they are a part.

In fact, Monsters, Inc. may just be the first Pixar film to graduate from childish entertainment to serving the role of educator to children that monsters are not something to be afraid of, but rather like most figments of one’s imagination, they should be enjoyed.

Unfortunately, movies such as Monsters, Inc., just as enjoyable figments of our imagination, come few and far between.

• Monsters, Inc. is Rated G