Box Office Chaos Erupts as ‘Avengers: Endgame’ Encore, ‘Forgotten Island’ and ‘Primetime’ Battle It Out This Weekend

Late September has quietly become one of the more unpredictable stretches on the annual theatrical calendar, a period when studios often gamble on original stories, animated adventures, and prestige counterprogramming rather than tentpole franchise fare. This year’s edition of that gamble looks especially chaotic.

Three very different films are converging on multiplexes within days of each other, each chasing a distinct slice of the moviegoing audience. Nostalgia, family entertainment, and awards-season ambition are all colliding in a way that’s making forecasters nervous about how the numbers will actually shake out.

Industry trackers now expect ‘Avengers: Endgame Encore,’ ‘Forgotten Island,’ and ‘Primetime’ to each land somewhere in the $18 million to $24 million range this coming weekend, setting up what could be one of the most genuinely unpredictable box office battles of the year.

‘Avengers: Endgame Encore’ brings the 2019 blockbuster back to theaters with a few extra minutes of footage, timed deliberately to build momentum ahead of ‘Avengers: Doomsday’ in December. The original film remains the second-highest-grossing movie of all time worldwide, trailing only ‘Avatar,’ and this re-release marks the first title in Disney’s new Infinity Vision premium format certification program.

AVENGERS: ENDGAME ENCORE as well as FORGOTTEN ISLAND and PRIMETIME are all tracking to make $18M-$24M this coming weekend. The most unpredictable weekend of the year, as @A24 strengthens its position as the new mine-major studio in Hollywood. https://t.co/hHLm4O8sqA
— Global Box Office (@GlobalBoxOffice) September 21, 2026

Early tracking pegged the re-release’s opening in the high teens to high $20 million, positioning it as a strong but not dominant player against the weekend’s newcomers. Given that it arrives sandwiched between ‘Spider-Man: Brand New Day’ and ‘Doomsday,’ the film carries considerable brand power even without new footage to sell audiences on.

Final trailer for DreamWorks' ‘FORGOTTEN ISLAND’.

The film follows 2 best friends trapped in a mystical world but their only way of escape is to erase all their memories of each other.

In theaters on September 25. pic.twitter.com/O3UP6k7AUG
— DiscussingFilm (@DiscussingFilm) September 8, 2026

‘Forgotten Island,’ DreamWorks Animation’s new fantasy adventure drawing on Philippine mythology, represents a rarer breed in today’s marketplace: a wholly original property without pre-existing IP behind it. The film follows two best friends who stumble into a mysterious portal and must race to escape before losing their memories of each other forever.

Reassemble the team & relive the experience as Avengers Endgame: Encore returns to theaters September 25.

Tickets now available for IMAX and Infinity Vision screens: https://t.co/pZZ4PiOyQb pic.twitter.com/2wKSVG4FLz
— Marvel Studios (@MarvelStudios) August 25, 2026

Forecasters at Box Office Pro placed the film’s opening weekend range between $20 million and $30 million, putting it in the company of recent late-September family releases like ‘The Bad Guys’ and ‘Abominable.’ A softer outcome closer to $13 million to $14 million remains possible if awareness doesn’t pick up in the final stretch before release, though a stronger showing in the mid-$30 million range, similar to ‘The Wild Robot,’ isn’t out of the question either.

Then there’s ‘Primetime,’ the Robert Pattinson-led psychological thriller from A24 that’s arriving fresh off its premiere in the main competition at the Venice Film Festival, where it competed for the Golden Lion. Directed by Lance Oppenheim in his narrative feature debut, the film casts Pattinson as ‘To Catch a Predator’ host Chris Hansen, with Merritt Wever, Skyler Gisondo, and Phoebe Bridgers rounding out the supporting cast.

New trailer for ‘PRIMETIME’, starring Robert Pattinson as Chris Hansen.

The film follows Chris Hansen as he runs ‘How To Catch A Predator’ where he confronts adult men who think they are meeting minors to have sex.

In theaters on September 25. pic.twitter.com/GsQIkFQiWm
— DiscussingFilm (@DiscussingFilm) August 6, 2026

‘Primetime’ is widely viewed as A24’s early play for awards-season attention, positioning itself ahead of fellow contenders slated for October releases. The film’s arrival also underscores just how far A24 has come as a distributor, increasingly operating with the marketing muscle and release strategy of a true mini-major rather than a scrappy indie outfit chasing niche audiences.

What makes this particular weekend so hard to call is the sheer variety of competing appeals. A nostalgic Marvel re-release, a family-friendly animated original, and an awards-hungry true-crime thriller rarely find themselves fighting for the same multiplex real estate all at once.

Add in Brad Pitt’s ‘Heart of the Beast,’ also opening the same Friday, and theater owners are looking at one of the more genuinely competitive slates of the year. How audiences actually split their attention and dollars across these releases will say a lot about where moviegoer appetite currently sits heading into the fall.