Jake Muller was conceived in Edonia; his mother was a unknown American woman who was living in the foreign country at the time. His father was unknown for an extremely long period and was eventually discovered to be superhuman ex-Umbrella employee and villain Dr
Albert Wesker; his fatherhood to Jake was even unbeknownst to him.
While pregnant, Jake's mother flew back to America to ensure that he would be born and raised as an American citizen; he was brought up in a typical fashion and was raised to believe that his father was a great man - however Jake grew to feel the opposite as he got older; more so when his mother became ill and she fell behind on bills. As his so-called great father was not on the scene to offer any financial or emotional support it was completely up to Jake to try to help his small family.
He decided to become a mercenary, taking on small jobs in order to earn money and learn essential skills. One major job he signed on for took him back to where he was conceived; Edonia. Missions like this made him battle-hardened and more of a force to be reckoned with. From here he took on even more jobs across the globe. Things took a turn for the worst however when he found out that his team was sold out by a selfish mercenary and the team was decimated. Jake managed to survive, but the damage had been done; he now felt that comradery was irrelevant as he thought mercenaries only care about money and getting the job done - so Jake earned himself a reputation for just that; only interested in the bottom line.
Sometime after this change Jake found his way back to Edonia once again for a job and at the same time the US Government and secret group The Family (Both parties under the supervision of
Derek C. Simmons) were attempting to intercept and capture Jake due to his unique blood. The Family were working on the brand new C-Virus and they needed him as a
Test Subject. It was entirely possible that Jakes blood could contain antibodies which would eliminate the C-Virus which would destroy any viability of the virus as a weapon. Moreover they could also use the antibodies in his blood to further mutate the C-Virus, creating a stronger product.
A researcher who worked for The Family, Dr
Carla Radames travelled to Edonia under the false identity of a chemist with various samples of the C-Virus. She told the mercenaries that they were simple vitamin supplements; Jake and his team received injections - his team quickly mutated into
Zombie-like creatures named J'avo but unsurprisingly Jake was not affected; his antibodies fought off the C-Virus and he was left with no evidence of an infection. He commented to Carla that the effects of these 'supplements' packed "quite a punch" as he witnessed all his other peers transform. After this he became immune to the virus, making him an extremely valuable asset for The Family. Some
time after the incident, Sherry Birkin was sent by The Family to find Jake and bring him back to American soil; or at least bring back a sample of his blood.
When Sherry managed to locate Jake, she requested his blood as instructed - and he nonchalantly accepted on the proviso that he gets $50 Million US Dollars in cash as payment for one pint of blood; he concludes that he would've also been willing to work out a small payment plan where he would receive half now and half once goods have been received. Obviously these demands were farcical and would not be met and instead a hulking B.O.W. (Bio-Organic Weapon) named the Ustanak designed by Carla specifically to hunt down and capture Jake was unleashed on them; they managed to avoid capture at this time due bumping into a BSAA (Bioterrorism Security Assessment Alliance) team led by the legendary Chris Redfield who assisted them in defeating various powerful creatures and allowing them time to evade capture from the pursuer.
Unfortunately a short time later, Jake and Sherry were captured by the Ustanak when an escape attempt via helicopter didn't go quite right which resulted in the two having to bail out and take a parachute journey down to safety. The Family had their own forces battling against the BSAA resulting in casualties on both sides but the pair managed to survive; Jake also noticed that Sherry had an extraordinary healing factor due to her having some remnants of a G-Virus infection in her body from many years before. They took refuge in a small cabin but sooner or later they would be caught by the B.O.W. which had been on their tails.
They were taken to Lanshiang, China - the main home base of Carla and Neo Umbrella. It was at this point where Jake learned that his father was a man named Albert Wesker; up until this point he was unfamiliar with the name and everything he knew of his father had come from his mother. After this point the pair were forcibly experimented on for a whole six months in captivity; Sherry for her healing abilities and Jake for his virus-eliminating blood. The Family had gotten everything they wanted by this point and their grand plan was well under way. However, Jake soon got tired of his predicament and used his military skills to defeat a team of J'avo while he was being transported to a different location. In the confusion he managed to escape his bonds, cut off power to sections of the facility he was being held in and make contact with his de-facto partner Sherry.
During a lull in the commotion, the two found time to speak more about Wesker; Jake asked if Sherry knew anything about him at all and was surprised to find out that she did. Wesker and her father William Birkin were extremely close colleagues at Umbrella at one point, eventually became something quite like adversaries and both suffered dramatic ends so they shared many similarities. At this stage they needed to get their bearings; they worked out that they were in China and Sherry made contact with her dispatcher from the US Government, Derek C. Simmons with an update. Little did she know that Derek was also the leader of The Family and they were definitely not on her side. To her surprise, Derek was already in China; he travelled there to meet with Carla after things began to break down. Unfortunately for him he had no idea just how badly things had gotten between him and Carla. The BSAA were also in the area, responding to a bioterrorism alert - Lanshiang was full of extreme talent from both sides of the stage and everything was about to hit the wire.
Sherry and Jake escaped their prison on a stolen motorcycle en route to a rendezvous point set by Derek; and were unsurprisingly pursued by Neo Umbrella forces which they fought with assistance from Ada Wong, Leon S. Kennedy and Helena Harper; all three had also found their way to China for what was set to become a showdown. After a brief discussion between Sherry and Leon about what they were all doing there, Leon revealed that he was there to confront her handler Derek C. Simmons who was in fact the one responsible for the bioterrorism attacks across the world, namely in China and in Tall Oaks. At first, Sherry did not know how to process this information; to her, Derek was always on the side of good and could not possibly be the one who caused all of this destruction. For now, Jake was on Sherry's side; pressure from Leon to reveal Derek's rendezvous point was met with hostility from Jake who forced Leon to back off. However Sherry gave a bit of backstory to Jake; it was Leon who saved her from NEST and her father all those years ago, he is a man that should be trusted.
Her trust shaken, Sherry began to reveal the location of Derek to Leon but this was interrupted when their pursuer returned once again; it had managed to board a flight to China and continue it's mission to capture Jake. The two teams fought the B.O.W. which resulted in an electrical substation tower coming down which split the ground and created a huge explosion which forced the two parties to go their separate ways for now. Jake and Sherry continued on to their rendezvous armed with this new information and they hoped that Leon and Helena heard enough of their explanation to make their own way there too. Either way, they pushed on not knowing what to expect next.
Making it to Derek's rendezvous point, they were met with not only Derek but Leon and Helena as well. They had heard her; and subsequently Derek ordered Sherry to take the two into custody as he insisted that it was those two that caused the bioterrorism attacks and also killed the US President Adam Benford.
A stand-off now occurred between the two opposing factions with a rift steadily increasing between Sherry and Derek in particular; she still did not quite know who to believe and a battle initiated where bullets were flying on both sides, even Derek's goons were shooting at Sherry which added to her confusion even more. Jake managed to push Sherry behind protective cover and they both defended themselves but the number of J'avo were increasing by the minute until eventually they were outmatched; they were captured once more and found themselves waking up in an unknown facility deep under the sea.
Finally seeing the error of her judgement, Sherry apologised to Jake for taking Derek's side and believing all of his lies up until this point. They were now shackled, with seemingly no hope of escape; but their entrapments suddenly opened and Sherry took the opportunity to sneak through a conveniently positioned air vent which allowed her to retrieve all of their weapons and also get onto the other side of the door to unlock it for Jake.
They were naturally met with hostility as they escaped but on the way they met with some families faces; the very people who released them from their bonds - the BSAA's Chris Redfield and Piers Nivans; after a quick meeting Jake discovered that it was Chris who ended his fathers life and for a brief moment he was overcome with absolute rage; he pulled his weapon on Chris and was prepared to fire; Sherry stopped him, citing that there were more pressing concerns and she was correct.
They were all interrupted by a large C-Virus spreading B.O.W. named HAOS which forced the two groups to split; Chris and Piers stayed behind to eliminate the threat as it was their jobs in the BSAA; Jake and Sherry went the opposite way to escape.
In the final moments of their escape they were once again met with the Ustanak in a lava room; possibly a disposal area. The two fought their pursuer but it kept coming back; Jake had lost his weapon and turned to fighting the creature hand to hand; even knocking it down into the boiling lava pit wasn't enough to put it down. But by this point Jake had enough; the world was going crazy and this thing had been following him and Sherry across the globe.
She managed to get a weapon and aim it at the beast but she was so frightened at this point that she couldn't hold it steady; Jake helped her steady her aim and together they fired a perfect shot which killed the creature once and for all. Then they escaped and parted ways.
After the events that had occurred Jake decided hat he had been going about life all wrong; it was in his best interests to believe in others and work as a team. Communicating with Sherry one final time he said he would still send her his blood if required, but payment was now lowered from $50 Million US Dollars to a more affordable $50 US Dollars. His blood was then used to eradicate the C-Virus as a concern.
