Godzilla fans can be fickle, and the classic monster may go out with a whimper instead of a roar. “Godzilla: King of the Monsters” debuted in theaters this weekend, and the movie’s lackluster opening doesn’t bode well for the next installment. The new Godzilla movie barely topped Disney’s “Aladdin” during its second week in theaters, and with “Dark Phoenix” releasing next week, things are only going to get harder for the prehistoric reptile.

“Godzilla: King of the Monsters” opened at number-one at the domestic box office with a $49M debut, but that’s almost half of the $94M opening weekend that “Godzilla” had in 2014. With a 50% decline at the opening box office, Warner Bros. Picture may have a crumbling universe on their hands, and the studio is already locked-in to another release.

After the 2014 release of “Godzilla,” the studio released the 2017 spinoff “Kong: Skull Island” to capitalize on the film’s success. Directed by Jordan Vogt-Roberts and starring Tom Hiddleston, Brie Larson, Samuel L. Jackson, John Goodman, and John C. Reilly, the spinoff made $61M on its opening weekend and brought in $566M worldwide. With two successful films in the bag, the studio decided to greenlight “Godzilla: King of the Monsters” and “Kong vs. Godzilla.”

Following the decision to add two more Godzilla movies to the schedule, everything seemed to be going well. Stranger Things’ star Millie Bobby Brown joined the cast, and the studio brought in Kyle Chandler, Vera Farmiga, and Ken Watanabe to fill out roles in “Godzilla: King of the Monsters.” The new release would broaden its appeal with a younger and diverse cast, and the movie would set up “Kong vs. Godzilla.”

Now on the same weekend that “Godzilla: King of the Monsters” released in theaters nationwide, the studio is looking down the road at its troubled franchise. In the past, both Godzilla and Kong made most of their money through international audiences. “Godzilla: King of the Monsters” and “Kong vs. Godzilla” will most likely be successful films thanks to these markets, but with domestic interests dying, it seems unlikely that Godzilla or Kong will return after the two fight it out in the next movie.

Warner Bros. Pictures isn’t the only studio with dashed hopes of a Marvel-like connected universe; Universal Pictures poured millions into the creation of the “Dark Universe,” which was going to feature classic monsters like the Invisible Man, Wolfman, Frankenstein, and other characters.

Unlike Godzilla and Kong, which remain a moderate success, the Dark Universe struggled right out of the gate with its keystone release of Alex Kurtzman’s “The Mummy” in 2017. The film had a familiar title and an all-star cast including Tom Cruise, Sofia Boutella, Russell Crowe, and Annabelle Wallis, but critics and moviegoers instantly panned the movie. The first installment in the new universe made $31M on opening weekend, and while it still made over $409M worldwide thanks to foreign markets, the movie shattered the plans of the Dark Universe entirely. The film “Bride of Frankenstein,” which was due out this past February, will most likely never see the light of day, and “The Invisible Man,” starring Elisabeth Moss and Storm Reid, doesn’t even have to connect to any of the other stories.

Warner Bros. Pictures DC Connected Universe is another money-maker that failed to connect with audiences. While the collection of films had highlights like “Man of Steel, “Wonder Woman,” and “Aquaman,” the DCEU never could reach the same heights as its Marvel counterpart. One area that Warner Bros. Pictures has found success is horror, thanks in large part to James Wan interconnected “The Conjuring” universe. Stretched out across five films, the movies have already made over $1.5B for the studio, and “Annabelle: Comes Home” is scheduled to hit theaters this summer.

Before Iron Man and Captain America teamed up, studios went from one film to the next, pushing out sequels until they were no longer profitable. Each release tested the water, and when the well went dry, the franchise was put back in the freezer until it was time for a reboot. Disney’s unprecedented success with its 22 movie Infity Saga has studios constantly turning to spinoffs to increase the interest in sequels, but no one has been able to replicate Marvel’s schedule. Godzilla and his monster buddies will most likely end its theatrical run in the green, but it seems unlikely that another release will reignite fans interest in the classic monster.