Chris Columbus is, at this point, the movie studio equivalent of an explorer, the first guy to get somewhere, the one who plants the flag and moves on. When he made the first two films in the "Harry Potter" series, he made decisions that resonated through the entire seven movies, no matter how strong a voice anyone who followed him brought to the table.

On the first "Percy Jackson," he was obviously hired to give 20th Century Fox the same sort of franchise that Warner Bros. spun from all things Potter, and while it was nowhere near the same sort of cultural phenomenon, it did well enough, especially when international box-office was considered, and they did indeed end up springing for the sequel, which arrives in theaters tomorrow.

This time, however, there's another guy directing, and I suspect that Fox's goals have been scaled back a bit, and that they picked the director they did because they have had good luck with him on another youth-oriented franchise. I am not a fan of the "Diary Of A Wimpy Kid" books or films, but they are huge hits with my oldest son, and it's one of the first times he's decided that he is a fan of something completely on his own. He read the books on his own, checking them out from his school library, and he asked me for the movies over and over until I finally realized that it doesn't matter if I'm interested in them or not. He is, and that's what is important. He really likes the movies, and in particular, he's a fan of the first one, which was directed by Thor Freudenthal.

First of all, any movie featuring mythological creatures should be directed by a guy named Thor. That should just be part of the DGA's bylaws at this point. But I suspect the real reason he was brought in is because the "Diary" films are relatively modest affairs, and for "Percy Jackson: Sea Of Monsters," Fox wanted something smaller scale that would still appeal to the fans of the books. Working from an adaptation by Marc Guggenheim, that seems to be exactly what they've made. It is a fairly self-contained story, but with just enough of a cliffhanger at the end to keep fans on the hook. It is small scale in many ways, and Freudenthal's use of effects is pretty canny. He makes the most out of every monster or setting, knowing that he can't just throw everything at the audience with no regard for cost.

Logan Lerman returns as Percy Jackson, the half-human son of Poseidon, the Greek god of the sea. He is joined again by Brandon Jackson as Grover and Alexandra Daddario as Annabeth, and the three of them have a fine casual chemistry that works for the films. They're joined this time by Tyson, who turns out to be another son of Poseidon's, and Douglas Smith plays this cyclops teenager as sort of sweet and goofy until it's time for action, a one-eyed teenage Brendan Fraser. Pierce Brosnan and Luke Camilleri have been replaced this time around by Anthony Head and Stanley Tucci, but they're onscreen for a grand total of about ten minutes each.

For the most part, the film concerns a quest by Percy and his friends to find the Golden Fleece and bring it back to heal the tree that is responsible for the magical barrier that keeps their sanctuary, Camp Half-Blood, safe from the outside world The set things up in a quick opening sequence, then hustle the kids out onto their adventure as fast as possible. The "Sea Of Monsters" of the title is what we know more commonly as the Bermuda Triangle, but the real threat here is Luke (Jake Abel), the Lightning Thief from the first film, back to once again put the world in peril, this time by raising an actual Titan from the grave.

I felt like everything in "PJ: SoM" happened so easily, with so little resistance, that it didn't keep me terribly engaged, but the target audience argued with me vehemently in the car on the way home. Both of my sons flipped for the film, and the more they talked about it, I get why it appeals to them. They're Harryhausen kids, and they love monsters. There are manticores and a hippocampus and a big creepy Titan at the end, and that's pretty much all it takes at this age to make my boys happy. It helps that it's an appealing young cast, and Freudenthal makes sure to turn up the sense of humor just a bit, making the film fun first, with just a hint of scary at times.

The nicest thing I can say about "Percy Jackson: Sea of Monsters" is that I found the whole thing sort of cheerful and agreeable, and there was nothing about it that struck me as a major miscalculation. I think these stories are pure formula, but executed with enough style and sincerity to make it worthwhile for the intended audience. The film clearly ends in a way designed to lead into a third film, and both of my kids hope they get to see it at some point.

Mission accomplished, as far as I can tell.

"Percy Jackson: Sea Of Monsters" opens Wednesday in theaters everywhere.