Spoilers ahead for Ant-Man and the Wasp and Avengers: Infinity War.
Ant-Man and the Wasp is an enjoyable romp and a firmly a standalone romp in terms of an MCU movie. To understand it, you would only need to have seen the movies that have Ant-Man in them—Ant-Man and Captain America: Civil War. And that might be a bit confusing if you saw Avengers: Infinity War and wondered why everyone is so cheerful in a world where have the population has been turned to dust. And that’s because Ant-Man and the Wasp takes place before the events of Infinity War. But the film doesn’t definitively come to that conclusion until you reach the end-credits scene.
In the post-credits scene, Scott is headed into the Quantum Realm to retrieve some Quantum Energy that can be studied and perhaps used to heal Ghost. Scott’s doing retrieval while Hank, Hope, and Janet are overseeing the project at normal size. Scott goes down to the Quantum Realm, gets some energy, but when he asks the team to pull him back up, he gets no response. We cut back and see that Hank, Hope, and Janet have been dusted by Thanos and now we don’t know how Scott is going to get back to normal size.
It’s a scene that’s both necessary and completely wrong for this movie. It’s one of the big drawbacks of the MCU is that all the movies have to relate to each other so something as heavy as Infinity War still has to have a connection to something as lightweight as Ant-Man and the Wasp. It’s a really jarring way to “end” the movie (there’s another post-credit scene where we see that the giant ant standing in for Scott was spared, so at least there’s that) because it’s a bummer. How do you not feel bad for Janet Van Dyne, who just spent 30 years in the Quantum Realm only to be dusted a week after coming back to our world?
The more interesting part of the post-credits scene is what happens to Scott. Even the line at the end is “Ant-Man and the Wasp Will Return?”, and while we now know that The Wasp will probably be sitting out Avengers 4 (or she’ll be in a pocket dimension with the other dusted heroes and half of humanity), there’s the question of what happens to Scott, which isn’t a bad cliffhanger. Is he stuck in the Quantum Realm and he’ll miss all the fun, or will he find a way to get out and join the remaining superheroes?
We’ll find out when Avengers 4 opens on May 3, 2019.