(It is an unfortunate coincidence that this movie’s plot – with its talk of broken dams and rising flood waters – calls to mind the tragedy of hurricane Katrina.)

Word starts to spread that there is a boat several miles away that can lead animals to safety. Manny convinces everyone to follow him on a trek toward this boat. Accompanying him are saber-toothed tiger Diego (Denis Leary) and intellectually-challenged sloth Sid (John Leguizamo). Along the way, they encounter another mammoth named Ellie (Queen Latifah), who was raised by possums and therefore doesn’t realize that she isn’t one. Manny is excited to know that he is not, as rumored, the last surviving mammoth. However, in order to repopulate the species, he would have to convince Ellie of her real species identity and develop some sort of romantic relationship with her.

Unlike its predecessor, Ice Age: The Meltdown really doesn’t have much in the way of a story. There is a surprising lack of plot here. Mostly it’s just a series of vignettes as the characters try to get away from the flood zone. They encounter other animals, have little non sequitur adventures (like Sid being proclaimed a “Sun God” by a pack of other sloths), and fight some vicious underwater carnivores that are unloosed by the melting glaciers.

At some level, the movie paints itself into a corner with the ending, which I will not spoil. After being unexpectedly frank about both the potential threat of extinction and the food chain, the film implies that everyone lives happily ever after. Perceptive children may pick up on the fact that, in reality, these creatures probably don’t have much time left.

Despite a general sense of ambivalence toward the plot, I still recommend Ice Age: The Meltdown because it maintains many of the charms of the original, starting with the characters. Manny, Diego, and Sid are distinct, likeable heroes with personality styles that mesh in funny ways. The voice actors are well cast to play up this fact. (I mean, would you ever in your wildest dreams imagine that Ray Romano and Denis Leary would occupy the same film?) Queen Latifah makes a nice addition, as she always does. The actress is so genuine and so charming that she lights up any movie she’s in, even if we’re only getting her voice. Advancements in computer-animation have made these characters and their surroundings even better looking than they were before.

Although there’s not a great deal of plot to hold them together, the individual scenes are almost always clever and funny. I laughed when Sid led dozens of other sloths in a call-and-answer musical routine, not unlike Cab Calloway used to do with audiences when he performed “Minnie the Moocher.” (Sid, however, cranks the silliness up to ten.) Seann William Scott and Josh Peck do the voices of Crash and Eddie, the possum “brothers” of Ellie who provide moments of amusing chaos that the more mature characters must deal with. The scene where Crash demands to be flung from a tree branch for fun is joyful in its goofiness. I like too how the film presents all these characters as a family. They come together in a time of crisis and learn to put their differences aside so they can work as a team.

Then there is Scrat, the mascot (and, if we’re being honest, the true star) of the Ice Age pictures. He again pops up half a dozen times or more, still trying to hold onto a stray nut. This time, Scrat encounters a school of piranhas, a giant vulture, and the perils of sticking one’s tongue onto something cold. Every time he appears, big laughs follow. The manic little squirrel’s arc has a payoff that is hilarious, first for what happens to him, then for what doesn’t. His scenes are the film’s best.

For whatever it lacks in the way of a compelling story, Ice Age: The Meltdown still manages to give family audiences what they want and expect: lovable characters, gorgeous computer-generated animation, and laughter. The original Ice Age was better, but the sequel is not without its own appeal.

( out of four)

Ice Age: The Meltdown is rated PG for some mild language and innuendo. The running time is 1 hour and 30 minutes.