WARNING: SPOILERS

A great idea doesn’t necessarily make a great movie. David S. Goyer realized that if someone with Superman’s powers suddenly showed up on earth, people would freak and governments and militaries would marshal their forces. Then Zack Snyder turned it into “Man of Steel,” and “Batman v. Superman.” Damn.

The great idea here is that when Billy Batson turns into Captain Marvel, he may change appearance, voice, powers, but he doesn’t change personality or knowledge; he stays who he is: a 14 year-old boy. So it’s like Superman + the Tom Hanks movie “Big.” I wouldn’t be surprised if that’s how they pitched it. Best part? They didn’t blow it. They kept Zack Snyder away.

The “Big”/“Superman” thing was obvious from the first trailer, so I expected it, and expected to be entertained by it; and I was, mostly. It’s a little dumber than I thought, but it’s fun enough.

What I didn’t expect? The metaphor about the Democratic Party.

Worst job recruiter ever
Initially I was confused. We’re on a car ride to grandma’s house in 1974? With Lex Luthor’s dad (John Glover)? And the kid playing with a Magic 8 ball in the backseat being bullied by his father and older brother—is that supposed to be our Captain Marvel/Shazam? So is this thing set in ’74—around the same time as the Saturday morning live-action TV show—or is that our villain? Except with that timeline, Mark Strong would have to be my age—born in 1963—and ... oh, he is. Kudos, Mark. You look great for our age.

When the fortunes in the Magic 8 ball turn into squiggly symbols, the car crackles with energy, ice forms on the windows, and the kid, Thaddeus (Ethan Pugiotto), is transported alone to “the Rock of Eternity,” which is like an interdimensional cavern. There, an ancient wizard with a long white beard and staff (Djimon Hounsou) tells him he’s searching for a new superpowered champion to help the world. The champion must be “pure of heart.” A former champion, not pure of heart, went bad and released the seven deadly sins into the world. Oddly, those sins are still in the cavern, encased in whispering statues along the walls. So they’re both in the world and trapped in the Rock of Eternity? OK.  

Anyway, the kid fails the test (he reaches for an energy ball, which is a no-no or something), he’s transported back to Dad’s car, becomes histrionic and causes an accident which leaves asshole dad paralyzed for life. That’s our cold open. And we haven’t met our lead yet.

Billy Batson, a gosh-gee newsboy in the original comics, a twentysomething radio operator in the 1941 live-action serial, and a long-haired Tiger-Beat teen in the 1974 TV series, is, here, a young, pretty-eyed punk (Asher Angel of Disney channel’s “Andi Mack”). He suckers a pair of Philly cops so he can get into their patrol car and look up the address of the woman he thinks is his biological mom. He has a long list of possibilities in his notebook and she’s the only one not crossed out. Turns out she’s black. Then the cops arrive and bust his head open for suckering them. Kidding. It’s jokes and kid gloves. You know Philly cops. But he winds up in another foster home.

This one is about as nice as you can get—a big ramshackle house run by the Vazqueses: Victor (Cooper Andrews), portly, jovial, philosophical, and Rosa (Marta Milans), who looks like a harried Angelina Jolie. The kids include:

• Freddy (Jack Dylan Grazer of “Me, Myself and I”), a white, supertalkative, superhero-obsessed teen with a crutch
• Faithe (Darla Dudley of “This Is Us”), a supertalkative and superneedy black girl who dispenses hugs like a priest dispenses wafers at the Eucharist
• Eugene (Ian Chen of “Fresh Off the Boat”), a Chinese-American gamer/hacker
• Pedro (Jovan Armand), portly and reticent
• Mary (Grace Fulton), the eldest, getting ready for college

If I’d been thinking, I would’ve realized where this was going—particularly with Freddy and Mary—but I’m kind of glad I wasn’t. Once it arrived, it was a joy.

This foster family is large, loud and big-hearted but Billy keeps his distance. He’s got a foot out the door already. At school, Fawcett Central High—for Fawcett Comics, the publisher of Shazam in the 1940s—there are bullies, of course, and they pick on Freddy, of course, and so Billy has to stand up for him since he can’t for himself. Then the bullies give chase. Billy escapes to a subway, flips them off from behind closed doors, settles in; then the subway speeds up, the other passengers disappear, and the stops take on those squiggly symbols we’d seen in the Magic 8 ball. When the doors open, Billy’s in the “Rock of Eternity.” Good bit? He glances back at the subway map to check the stop.

Before all this, by the way, young Thaddeus (now a glowering Mark Strong), had set up a research institute investigating incidents like his from ’74—the hieroglyphics, the transportation, the wizard, the offer of power, the test, the failure—which has happened to dozens of people around the world. When the symbols are finally captured on video, Thaddeus figures out the pattern: the seven symbols that need to be repeated seven times to open the gateway. That’s what he does. He returns, pushes the old wizard aside, absorbs the seven deadly sins, and accumulates vast power to wreak havoc on the world. To be sure, we mostly see him wreaking havoc on his father’s company. He tosses the older brother out the window, unleashes the seven deadly sins to kill board members in horrible ways, and saves Greed to tear his father apart limb from limb. Oddly, he doesn’t stay to watch it. You’d think after nearly a half-century of hatred and resentment, he might.

So with the seven deadly sins gone from the Rock of Eternity, is that why Billy passes the test? Because there is no test? So why was he chosen then? He’s not exactly pure of heart. Why isn’t Faithe chosen? Or Mary? Or Victor Vasquez for god’s sake? Maybe there was an answer and I missed it.

This is the part where I got whiffs of the Democratic party. Old man Shazam has spent at least 45 years searching for a replacement, a champion, to take over; and he’s interviewed dozens, maybe hundreds, maybe thousands, and none of them passed his purity test. Meanwhile, evil gathered.

But forget the metaphor. How much of a fuck-up is this Shazam? He keeps picking people who can’t pass the test, and probably fucks them over for life; and one of them becomes so incensed, and obsessed, he becomes a supervillain. And he seemed like a decent kid at the start! That’s some shitty program.

Anyway, I assume that’s why Billy Batson, who isn’t exactly pure of heart, gets the gig. At this point, they needed to pick somebody. And he says “Shazam!” and turns into what would be called Captain Marvel (Zachary Levi in a padded suit) but for copyright issues with Marvel Inc. That actually leads to a good bit, as he and Freddy, but mostly Freddy, try to come up with different names for him: Captain Thunder, Captain Sparklefingers, Thundercrack, Mr. Philadelphia, Zaptain America, Sir Zaps-a-Lot.

I anticipated this being my favorite part of the movie and it was. Among the antics he and Freddy get into:

• testing CM’s superpowers
• buying beer
• sipping beer and spitting it out
• buying tons of candy instead
• going to a “Gentleman’s Club”—CM at least

He stops crooks at a convenience store, then rescues an attractive woman from a purse-snatching. Except he pisses her off by calling her an “old lady” and she’s already maced the purse-snatcher. He wasn’t needed. Another good bit.

Along with “Big,” some of it reminded me of “Greatest American Hero,” the short-lived but often-funny superhero show of the early’80s, starring William Katt as a schoolteacher who is given a superhero suit but loses the instruction book: He’s forever flying into walls and things. He’s the George of the Jungle of the city. Similarly, Shazam doesn’t really know what he can do or how to do it. Takes him forever to figure out flying. But as they’re testing all he can (and can’t) do, Freddy video-records it and uploads onto YouTube, where it gets tons of hits. The true source of 21st-century power. Question, though: Couldn’t anyone with skillz trace the videos back to Freddy? And thus his family? Not exactly smart. 

Foster Family: the new FF
Eventually the fun ends when Thaddeus, now Dr. Sivana, the longtime Captain Marvel villain, shows up, envious that another champion was chosen. I’m curious what he’d been doing after the boardroom. Does he have a plan? World domination or anything? Does he and the 7 Deadlies just want to wreak havoc? It’s electing Trump, isn’t it? I bet it’s electing Trump.

Sivana makes quick work of Shazam, who is new to his powers, and just a kid, after all. I like this part. Superpowers don’t a superhero make. Just because you’re super doesn’t mean you’re brave. Billy/Shazam flees, and it takes his foster family being threatened before he begins to fight back against someone whose powers seem greater than this. Oh, and in the process, he finds his real biological mom, who’s an awful person. His real family is the foster family, and they turn into—of course—the Marvel family: Freddie becomes Captain Marvel Jr. (if he could be so named), Mary is Mary Marvel. Etc. Each has one of Shazam’s powers.

I liked that. I like the “family you create” motif, which is very Hollywood. Even so, that, along with the mid-credits sequence introducing Mister Mind, who is, after all, a fucking caterpillar, reminded me that C.C. Beck’s world was always kind of stupid. (Mouse over the poster for an example.) Tawny Tiger? Captain Marvel’s shortie cape and his Brezhnev eyebrows? Holy Moley? Superman gets “Man of Steel” and “Man of Tomorrow,” Batman gets “Caped Crusader,” and the best nickname Beck can come up with is “The Big Red Cheese”? Even as a kid I thought Shazam comics were dumb. They were dumb by the standards of Golden Age comics, let alone the Mighty Marvel Age I was living in.

So congratulations to screenwriter Henry Gayden (“Earth to Echo”), director David F. Sandberg (“Lights Out”), and the cast and the casting director. DC is finally turning it around. Before, they had great source material and turned it into crap; now, they have crap source material (Wonder Woman, Shazam!), and are turning it into something, if not great, at least fun and palatable.

Don’t envy them Mister Mind, though.