Ant-Man And The Wasp was going to tie into Avengers 4, but for most of the movie, it’s not on your mind. Mostly what is is that Michael Peña should explain the plot of every Marvel movie. But once you get past the first round of credits, the movie ties into Avengers 4 in a fairly big way. Spoilers below!
Before we get into it, if you’ve wandered down here and want to remain unspoiled before you see the movie, have a lovely parting GIF:
Still here? So, one of the big McGuffins in the movie is “quantum healing particles,” which are useful just by their name. The post-credits scene starts with Scott Lang (Paul Rudd) getting ready to dive into the Quantum Realm while Hope Van Dyne (Evangeline Lilly) and her parents (Michael Douglas and Michelle Pfeiffer) work ground control. Ant-Man shrinks, entering the quantum realm via a “quantum tunnel,” gathers the particles, and asks to get sized back up.
As you might have already guessed, in the interim, Thanos’ snap happens and the entire Van Dyne lineage doesn’t feel so good. So that’s where we leave Scott: Stuck in the quantum realm, holding a big handful of “healing particles,” and not sure what to do or even with a method of escape. A second post-credits scene implies San Francisco, Ant-Man’s home base, is particularly hard-hit by Thanos’ snap.
This doesn’t quite answer why Ant-Man wasn’t in the battle at Wakanda, but it does set up where he is in Avengers 4, and it’s particularly intriguing that he’s trapped in the Quantum Realm. Fans might remember that the Realm is a place where time doesn’t operate at the same scale or speed, and also opens the door to different realities. It may even be out of Thanos’ reach, or at least his awareness.
Of course, there’s also a fail-safe in the form of a character we meet in the movie, Bill Foster (Laurence Fishburne), so Scott might just get yanked out and run off to beat up Thanos on his farm. But it seems more likely Thanos will come across a very tiny spanner in his works, even if Scott is only there by accident.