WARNING: The following article contains spoilers for Ant-Man and the Wasp, in theaters now.
One criticism the Marvel Cinematic Universe has faced from the beginning is a lack of formidable villains, not just physically, but mentally. For years, Loki and the Winter Soldier were the only ones worth much of anything, with the likes of Whiplash, Malekith and the Mandarin garnering Marvel Studios serious flak.
Director Peyton Reed now finds himself improving on Ant-Man's Yellowjacket by creating an enemy audiences can connect with emotionally and empathize with in the form of Ghost (Hannah John-Kamen) in Ant-Man and the Wasp. And in crafting the character's tragic backstory to her current predicament of trying to find a means of survival, he's shaped the MCU's most tragic villain to date.
Reed doesn't go down the emotionally complex route at all here, instead proving simplicity works when it comes to crafting a solid arch-nemesis. At first glance, it seems Ghost is your typical villain, stealing technology (namely, the Quantum Tunnel) from Hank Pym (Michael Douglas) and Hope van Dyne (Evangeline Lilly). This is all so she and the double-crossing Bill Foster (Laurence Fishburne) can extract Janet van Dyne aka the original Wasp (Michelle Pfeiffer) from the Quantum Realm themselves.
Now, seeing as Reed smartly had Sonny Burch (Walton Goggins) attempting to steal the tech as well, albeit to sell on the black market, one assumes Bill and Ghost want to do the same. But it's soon revealed Hank and S.H.I.E.L.D. are responsible for creating Ghost and weaponizing her. As her origin unfolds, we see Hank firing Ghost's father from his science team for shady activities. While it was deserved, Hank being Hank does so with a bit of arrogance, something he was known for back in the day.
Ghost (who was a young girl named Ava back then) moved to Argentina with her father, who's obsessed with outdoing Hank, but when he tried to create his own Quantum Tunnel, the energy expelled kill him and his wife, leaving Ava an orphan. Sadly, the energy caused her body to remain in a state of perpetual flux, with destabilized molecules leading to her constantly shifting phases. Bill, feeling sympathy towards her, takes her in, but his employers, S.H.I.E.L.D., spot her potential and turn her into an assassin. He gets no help from his boss at the time, Hank, as he tries to stop them from ruining Ghost's life. This is what led to the fallout between the two intellects.
Eventually, Bill and Ghost part ways with S.H.I.E.L.D. when the organization fell in Captain America: The Winter Soldier, but they're left with a more pressing matter: Ava's body needs to be stabilized with mere days left before she fades away into nothingness. They're hunting Janet as they believe they can extract the same quantum energy from her which affected Ava, and stabilize her once again. If this fails, well, at least they'll still have the tunnel to use themselves.