OK, so a cinematic spin-off of Harry Potter means you're trying to fill some pretty big shoes, but looking at who is behind it, it should be a sure-thing, right?

OK, so a cinematic spin-off of Harry Potter means you're trying to fill some pretty big shoes, but looking at who is behind it, it should be a sure-thing, right?

Sadly, no. I guess even if you mix the right parts, sometimes the potion just fizzles.

"Fantastic Beasts and Where to Find Them" has Potter creator J.K. Rowling making her screenwriting debut, expanding on the concept of her "Fantastic Beasts" book. It's directed by David Yates, who directed the last four Potter films.

But, despite some eye-popping effects and a return to the wizard world fans love, "Beasts" has a harder time connecting with its characters. It's solid entertainment, but pales in comparison to the Potter saga.

Newt Scamander (Eddie Redmayne) arrives in 1926 New York City after a fantastical journey. He carries only a nondescript suitcase. Of course, in this world, it's anything but. Inside are dozens of magical beasts.

And, of course, some of these beasts don't stay in the suitcase, which sets Newt off on an adventure with a fellow magician named Porpentina "Tina" Goldstein (Katherine Waterston) and a "No-Maj" (what Americans call Muggles) named Jacob Kowalski.

Of course, it's hard to leave the confines of Hogwart's and Harry, Hermione and Ron. With the emotional investment audiences made in those characters and that world, it's an unfair comparison.

But also that nostalgia is what "Fantastic Beasts" is counting on. Even though it's set long before the events of the Potter series, it counts on a few timely shoutouts. And waiting for that sense of wonder to kick in is what sets "Beasts" up as a disappointment.

It's not that it doesn't pop and isn't a lot of fun. The 1920s New York setting turns into a disaster movie setting, but with a more whimsical touch - and that actually works.

But both Yates and Rowling are both obviously in new territory, and there are some fumblings.

Rowling's first foray into screenwriting - the Potter screenplays were all adapted from her novels by other writers - highlights some of the differences between writing a novel and writing for the screen.

As a result, "Beasts" is overloaded with underdeveloped characters. It actually feels like an adaptation of a more fleshed-out story.

In his previous efforts, Yates was dealing with established and beloved characters and just needed to keep the action moving. "Beasts" becomes a bit scattershot as it alternates between action and building to a larger drama that lacks clarity.

This is the beginning of a series, and it offers passable entertainment for fans, but let's hope it gets better.