A big campaign has begun after the first showing of the new Marvel blockbuster, Avengers: Endgame.
The long-awaited movie comes out in the UK on Thursday 25 April, and loads of people are desperate to find out what happens to loved characters like Captain America, Iron Man, Loki and Black Panther.
But one of the big worries is that once the film comes out, early watchers will blab about what happens and will ruin it for everyone else.
Now, the directors have put a special poster on social media encouraging people to not reveal any spoilers, using the hashtag #Don'tSpoilTheEndgame
Do spoilers ruin films for you? Let us know in the comments below.
After the film premiere earlier this week, loads of the stars went to put their hands on the Hollywood Walk of Fame.
But they weren't giving anything away about the plot of the film.
The poster isn't the first attempt to encourage people not to spill any secrets about the film.
Earlier this year, the directors wrote an open letter to fans to encourage them not to spoil the film for others.
This comes after leaked footage from the film made its way online.
The spoiler-heavy footage was filmed on a mobile phone and shared on social media, before being removed.
Joe and Anthony Russo, who directed the new film, have asked: "When you see Endgame in the coming weeks, please don't spoil it for others, the same way you wouldn't want it spoiled for you."
"Remember, Thanos still demands your silence."
The directors have worked really hard to try to keep the film a surprise for fans - and even the actors!
Karen Gillen, who plays Nebula said that the actors were only given the scenes they were in, to keep the biggest secrets hidden.
And, according to an interview with Robert Downey Jr who plays Iron Man, Tom Holland - the actor who plays Spider-Man - had been given scripts with fake information in, as he is known for accidently revealing spoilers!
Eleven years and 21 films later, Avengers Endgame will be the final film in the Infinity Saga. The film will be out on 25 April.