"The only thing more tiring than going that big, is putting up with Hank's bullshit."
―Bill Foster to Scott Lang[src]

Doctor William Barrett "Bill" Foster is a biochemist and a former member of S.H.I.E.L.D. who had previously worked with Hank Pym on Project G.O.L.I.A.T.H. until disagreements between them caused Pym to dismantle the project. During one of the S.H.I.E.L.D. mission, Foster met Ava Starr, a young girl whose exposure with the Quantum Realm caused severe damage to her body. Once S.H.I.E.L.D. had collapsed, Foster helped Starr cure her condition, using all research that Pym was doing to bring Janet van Dyne back from the Quantum Realm, while both Ant-Man and the Wasp stood in their way. Although he disagreed with her methods, Foster continued helping Starr until van Dyne was saved and cured her, as Foster agreed to protect Starr as they went on the run.


Early Life

Project G.O.L.I.A.T.H

"I was partners with Hank on a project called G.O.L.I.A.T.H.."
―Bill Foster[src]

Working for S.H.I.E.L.D., Foster worked with Hank Pym on Project G.O.L.I.A.T.H.. During the project, Foster was able to grow to at least 21 feet. However, Foster and Pym had a fight and Foster left the project before Pym decided to leave S.H.I.E.L.D.[1]

Meeting Ava Starr

"Hello, Ava. My name is Bill. I was a friend of your father. I brought you something. It's all right. Try again. That's it."
―Bill Foster to Ava Starr[src]
Young Goliath

Foster meeting Ava Starr

Years later, S.H.I.E.L.D. assigned Foster to investigate the quantum anomaly in Argentina. After the investigation, Foster learned that anomaly was caused by Ava Starr, daughter of his former colleague and friend, Elihas Starr. Starr's work with Quantum Tunnel led to their eventual death of his wife Catherine, as well as himself, while their daughter was inundated by quantum energy. Foster took her from the orphanage becoming her surrogate father and vowed to find a cure for her condition. Despite his protection, he wasn't able to prevent S.H.I.E.L.D. from running tests on her and turning her into a killing machine.[1]

A Cure for Ava Starr

"When S.H.I.E.L.D. collapsed, I took Ava in. I built the chamber to slow her decay, but her condition was progressive. I didn't know how to cure her. She wanted to kill you, Hank. But I told her, no. And that she should watch you instead. And sure enough, she discovered that you were building a Tunnel."
―Bill Foster to Hank Pym[src]

In the wake of HYDRA Uprising and the collapse of S.H.I.E.L.D., Foster took Ava Starr away but her condition continued to mature, but so did her molecular instability. Eventually, her condition reached a point where any kind of instability was incredibly painful and even her suit became less effective at helping her control it. Foster designed the Quantum Energy Chamber where Starr could be bombarded by quantum energy to help stabilize herself, but it only offered a very short-term solution. They realized that in order to cure Starr for the long-term, she would need heavy amounts of quantum energy, and Foster realized there might be one place they could get it: the Quantum Realm.

Despite Starr's intention to kill Hank Pym, Foster prevented it and told her to only watch him. Eventually, she found out that Pym had reopened work on the Quantum Tunnel in order to bring back his wife Janet. Foster began plotting with Starr to steal the shrunken-down lab so that they could drain her quantum energy and heal Starr, at least for a long period of time.[1]

Reunion with Former Friend

AMATW Fishburne

Foster lectures his students about biochemistry

"I told you this was a waste of time. Come on, let's go."
"Don't condescend, Hank. You're the one who's on the run from the FBI. All because you had to grow to a size that finally fit your ego."
"That wasn't me in Germany. It was this idiot."
Hank Pym and Bill Foster[src]

While Foster as lecturing for his students at Berkeley University, he spotted Hank Pym, Hope van Dyne, and Scott Lang in an auditorium and finished his lecture sooner, letting students go. They told Foster about their plan, as well as the link between minds of Lang and Janet van Dyne, much to Foster's curiosity. Van Dyne asked Foster to help in the search for Mobile Laboratory kidnapped by Ghost, however, Foster said that he did not have the equipment they were describing to him.

Ant-Man and the Wasp 96

Foster meets with Hank Pym, Hope van Dyne and Scott Lang

Pym expressed his annoyance, noting that their visit to Foster was a waste of time while Foster asked him not to be condescending. Foster then noted that Pym was on the run from the FBI because he had to grow to a size of his ego, pointing to the incident in Germany. However, Pym stated that he was not in Germany and it was Lang which surprised Foster. He talked back with Lang about his job with Pym at the Project G.O.L.I.A.T.H. back in S.H.I.E.L.D., commenting that he was forced to tolerate the grouching of his partner. They then discussed their records for growth, with Foster being a proud 21 feet and Lang trumping him with a colossal 65 feet.

Van Dyne interrupted them, hinting that they need to focus on the search of the lab. Foster mockingly expressed his surprise that Pym still had not already figured how to do it and then noted that Pym's arrogance was the reason why he left the project. Pym reminded that he fired Foster, but he still kept remonstrating Pym due to his temperament, stubborn and impatient which pushed everyone away from him, except for Janet who in the end paid her price.

Pym then could not take Foster's attacks and be going to assault him only to be stopped by Lang and van Dyne. Lang then spotted FBI agents led by Jimmy Woo outside of the campus, saying that they must leave right now. Ultimately, Foster advised that they use a regulator from an Ant-Man Suit to track the lab. Van Dyne admitted that Foster's idea can be helpful and thanked him before they left his office. However, Foster actually intended to lure them to Ghost's Hideout where he can extract information about the Quantum Realm from Lang.

Woo visited Foster in his office and informed him that campus police identified his previous visitors as Pym and van Dyne, however, Foster denied his suggestions. Foster told Woo that he did not meet Pym for thirty years and he definitely was the last person he would want to visit. Stoltz did not believe him and tried to push on Foster before he was stopped by Woo. He wanted to know the reason of malice between Foster and Pym what he calmly replied that they hated each other.[1]

Ambush at Ghost's Hideout

"For the last 30 years, she's been down there absorbing quantum energy. We can extract that energy. We can use it to repair Ava's molecular structure-"
"Extract it?"
"Are you insane? That would rip Janet apart!"
"You don't know that. I'm gonna fire up your Tunnel. When Janet's location pops into Lang's head, he's gonna give it to me or I'm gonna turn him over to the FBI."
―Bill Foster and Hank Pym[src]

Foster's plan succeeds and Ant-Man, Wasp and Hank Pym were captured by Ghost inside her hideout. Foster then revealed himself as Starr's ally in front of them while Starr explained her intentions, telling about her father who was discredited and fired by Pym. Elihas' work on the Quantum Tunnel caused an explosion what killed Starr's parents and distorted her molecular structure.

Foster then explained that he took Starr away after the collapse of S.H.I.E.L.D., and searched for a method to stabilize her condition. However, Foster's monologue was interrupted by Lang's phone. Foster said that Lang was called up by his daughter Cassie but refused to allow Lang to answer her. Lang then convinced him that it probably something important (what actually was not). Foster then told Pym that the only way to help Starr is extracting Janet van Dyne's quantum energy which could stabilize Starr's molecular structure. However, Pym furiously protested, saying that it will kill Janet, much to Foster's skepticism.

Foster stated that Lang will inform him about Janet's message about her location, otherwise, he will turn them to the FBI. He then used Pym Particles Disks to reduce Quantum Energy Chamber and prepared to go, leaving Pym and van Dyne in the hideout. However, Pym was seemingly suffered by a heart attack and van Dyne and Lang him to gave Pym his medicine. After the hesitation, he decided to help his former friend and took a box with Pym's pills. Starr realized that it was a lie but too late, Foster released increased ants that kept Foster and Starr away. Pym used EMP Communication Device to keep Foster away while van Dyne and Lang knocked Starr and escaped with the Mobile Laboratory and Quantum Stabilizer.[1]

Keeping Plan in Motion

"What if Hank was right? What if this process kills Janet?"
"You're worried about her?"
"All I'm saying is she's a brilliant scientist. She may be able to help."
"Oh, she will help. Right now. And if she dies, she dies!"
―Bill Foster and Hank Pym[src]

Without ants in the Ghost's Hideout, Foster examined the condition of the Quantum Energy Chamber, figuring out that they need the Mobile Laboratory. He explained to Starr that chamber, as well as the suit, cannot help her longer and she had a few weeks to live. Starr was going to force them to bring the lab back and intended to kidnap Cassie Lang as a ransom. Foster stopped her, noting that he tolerated a lot of Starr's issues but he can not be a part of the kidnapping of a child. Starr furiously reminded him that she is fading away and Foster promised to fix it. However, he said that if Starr hurt Scott Lang's daughter, he would not help her. Starr had no other option but agree to Foster's condition.

Later, Starr managed to steal the laboratory, while Hank Pym and Hope van Dyne were arrested by the FBI. Foster set up the equipment, connecting the Quantum Tunnel with the chamber and stated that tech is ready to extracting energy. However, Foster also explained the procedure could be very dangerous and they probably should wait. Starr reminded him that she has no time to wait and they need to do it right now.

Foster then attempted to launch the Tunnel however it immediately shut down. Foster saw several ants sabotaging the equipment and figured out that Pym is close. Starr then went to deal with them, leaving Foster in the lab where he was ambushed by giant ants. Keeping Foster away, Pym took his suit and was going to the Quantum Vehicle. Foster then said that he just wanted to help Starr and Pym assured that he will help him to stabilize her condition once he saves Janet van Dyne, saying that together they can figure something out. Foster said good luck to Pym before ants escorted him out of the lab before it was reduced Lang and van Dyne.

Group leaves the area

Foster leaves the Mobile Laboratory

Later, Foster saw the decreased lab and realized what Starr was intending to do. Foster attempted to stop her from extracting the energy, explaining that Pym could be right that it will kill Janet. However, Starr did not care about her and pushed him away before turning on the chamber. The process was launched and Janet became to lose her structure but Starr was stopped by Lang and van Dyne. Janet then cured Starr's condition, much to Foster's joy. Luis then informed them that San Francisco Police Department is coming there and Lang proposed to get away. Together with Ava Starr, Foster managed to hide from the police and then Starr asked him to leave her behind. However, Foster refused to leave her and they hugged before continuing hiding.[1]


"You said it yourself. I've hurt people. But you haven't. Go, please."
"We can make it, Ava."
"I'm not leaving you."
Ava Starr and Bill Foster[src]

Foster is an exceptional and intelligent scientist on par with Hank Pym enough for the latter to consider him his rival. He, however, resented Pym for his ego and attempt to fire him. From this point on, he develops a fierce hatred for Pym, deriding his egotistical nature and arrogance. Beyond this resentment for Pym, however, he's rather kind and affectionate, getting along quite well with Scott Lang upon meeting him and commenting on his size-increasing trials in the old days.

It is later revealed that Foster deeply cares for Ava Starr, doing whatever he could to heal her of her condition. This love is so deep that he treats Starr like his own daughter, tolerating several of her more ruthless actions, and refused to leave her side, even when his life was at risk. Despite his love for her, Foster's tolerance for her actions has a limit; this is particularly seen when Starr suggested kidnapping Lang's daughter. Foster vehemently rejected the idea, going so far as to say if she laid one finger on her, he would no longer help her.

Additionally, he showed last-minute hesitation at absorbing quantum energy from Janet van Dyne, worrying that Pym may have been correct about van Dyne being ripped apart by the process, and urged Starr to find another way. Despite Starr's attempt to push him away, Foster could not turn his back to her and decided to went off the grid with her.

Powers and Abilities


"How big did you get?"
"My record? Twenty-one feet."
Scott Lang and Bill Foster[src]
  • Size Manipulation: Using technology designed with Hank Pym, Foster was able to grow his body to giant size, up to 21 feet.


"In an isolated system... particles co-exist in a stable phase relationship. If the system is interfered with, that stability becomes chaos. Unpredictable. Dangerous. Beautiful. Isolated completely, a quantum system would revert back to separate states of matter... each entangled with a distinct state of its environment. In other words, the object in question would be both in and out of phase... with multiple parallel realities."
―Bill Foster[src]
  • Master Scientist: Foster is an excellent S.H.I.E.L.D. scientist, working with Pym, and Janet van Dyne. He had a solid background on quantum technology and worked with Pym on Project G.O.L.I.A.T.H. He was also able to build an advanced machine to momentarily halt Ava Starr's molecular instability, and later assisted Pym to locate his mobile lab by advising him to modify the defraction units one of his regulators to improvise a tracker.


  • Quantum Energy Chamber: In order to stabilize Ava Starr's molecular condition, Foster designed the chamber that bombarded her by quantum energy, stabilizing Starr. However, it was only a very short-term solution and later it lost effect. Foster then re-designed the chamber to extract quantum energy from Janet van Dyne.
  • Pym Particles Disks: Foster used one of the disks with Pym Particles to reduce the Chamber and carry it out of the hideout.







Behind the Scenes


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The Marvel Cinematic Universe wiki has a collection of images and media related to Bill Foster.
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