Warner Bros.’ “Joker: Folie a Deux,” a dark new musical Batman spinoff, earned an estimated $40 million over the weekend to top the North American box office, industry watchers reported Sunday.

But that was far behind the $96.2 opening of the original “Joker” in 2019, a movie that earned Joaquin Phoenix a best-actor Oscar and grossed more than $1 billion worldwide. Industry analyst David A. Gross called it “a weak opening for the follow-up sequel in a superhero series.”

“Folie a Deux” -- French for “shared madness” -- again stars Phoenix as the unbalanced titular villain, this time joined by Lady Gaga (playing the cheerily deranged Harley Quinn) as the two sing, dance and plan assorted acts of mayhem. Todd Phillips directs, and the cast includes Brendan Gleeson and Catherine Keener.

Last week’s box office leader, family-friendly sci-fi tale “The Wild Robot” from DreamWorks Animation, slipped a spot to second, taking in $18.7 million for the Friday-through-Sunday period, industry watcher Exhibitor Relations estimated.

English actor Leigh Gill attends the US premiere of Warner’s “Joker: Folie a Deux”.

US director Todd Phillips attends the US premiere of Warner’s “Joker: Folie a Deux”.

US actress and singer Lady Gaga and US actor Joaquin Phoenix attend the US premiere of Warner’s “Joker: Folie a Deux”.

US actor Hudson Oz attends the US premiere of Warner’s “Joker: Folie a Deux”.

Argentine-US director Andres Muschietti attends the US premiere of Warner’s “Joker: Folie a Deux”.

Lupita Nyong’o voices Roz, an intelligent robot who is marooned on an uninhabited island and, to survive, has to befriend a menagerie of woodland animals -- and ends up adopting an adorable gosling.

Warner Bros.’ “Beetlejuice Beetlejuice” also slipped a spot, to third, earning $10.3 million.

Michael Keaton again plays the creepily hilarious title character with Winona Ryder reprising her role as Lydia Deetz, backed by “Beetlejuice” newcomers Jenna Ortega, Monica Bellucci and Justin Theroux.

In fourth was Paramount’s animated action film “Transformers One,” the latest installment in the toy-based franchise, at $5.4 million.

And in fifth, for the second straight week, was “Speak No Evil,” a psychological horror film from Blumhouse and Universal Pictures, at $2.8 million. James McAvoy and Mackenzie Davis star.

Rounding out the top 10 were:

“White Bird” ($1.5 million)

“Deadpool & Wolverine” ($1.5 million)

“The Substance” ($1.3 million)

“Megalopolis” ($1.1 million)

“My Old Ass” ($908,000)—AFP