The MCU has left several unresolved plotlines along the way, chief among them being the tease of Samuel Sterns becoming The Leader in The Incredible Hulk. Over ten years have passed since actor Tim Blake Nelson first transformed into Hulk's archnemesis, and soon he will return in Captain America: New World Order.
Under the alias of Mr. Blue, Sterns communicated with Banner during his time on the run in an effort to find a cure to his Hulk condition. The scientific duo were eventually able to synthesize a temporary antidote to his Hulk condition but descended into an argument as Sterns had further ambition for the research.
Sterns was also, not by choice, the scientist responsible for the creation of the Abomination. The Leader-to-be was held at gunpoint by Emil Blonsky and forced to inject him with Banner's blood, adding to his government-infused Super Soldier Serum and ultimately creating the Abomination.
After Blonsky underwent his first rage-fueled transformation into the Abomination, he trashed Sterns' lab and injured the scientist in the process. Having suffered a wound to the forehead, Sterns was exposed to the Hulk's blood, causing his head to grow in size and a twisted smile to appear on his face; The Leader was born.
That was the last time Sterns was seen on-screen, and with no Hulk solo movie having been made in 14 years, fans feared the worst for The Leader's story. But, as Hulk's corner of the MCU is being revisited in She-Hulk, The Leader was revealed to be coming back as the main villain of Captain America 4.
Even though the insight may be minimal on where Sterns has been all these years, one MCU tie-in comic offers a taste of The Leader's story after The Incredible Hulk, revealing a secret interaction with Scarlett Johansson's Black Widow.
The Leader's Untold Story in the MCU
The Leader may last have appeared on MCU screens in 2008's The Incredible Hulk, but Samuel Sterns returned once already in Fury's Big Week - an MCU comic prelude to The Avengers that expands on the events of The Incredible Hulk, Iron Man 2, and Thor, all of which take place in the same week.
After General Thaddeus "Thunderbolt" Ross began his mission to hunt down the Hulk, Nick Fury sent Black Widow to the scene to bring in Bruce Banner instead.
Black Widow came across a stranger calling for help at the sight of Abomination's creation, this turned out to be the freshly gamma-infused Samuel Sterns.
The SHIELD spy quickly recognized Sterns by name, only for him to share his belief that "perhaps once [he] was," indicating the mental significance that has immediately come with his transformation into The Leader.
The Leader had already begun formulating what clearly sounded like a villainous plan as he plotted out his "illustrious future driven by power and influence," an endeavor he attempted to recruit Black Widow into.
As one would expect, Scarlett Johansson's Avenger was not on board with the plan and proceeded to shoot him in the leg before calling for an extraction team to bring him into SHIELD custody.
The Leader was later seen at the site in which SHIELD was developing its super-powered Phase 2 weapons. Sterns was kept at the lab in a tank of liquid and being studied under the codename "Project Mr. Blue" - a reference to the codename he went by to communicate with Bruce Banner in secret.
What Will The Leader Do in Captain America 4?
So, assuming Marvel Studios opts to consider the Fury's Big Week tie-in comic as canon, The Leader was last seen being studied in SHIELD custody. But as HYDRA was operating within SHIELD at that time, there's every chance there may have been more villainous things going on in those experiments.
Nonetheless, with the fall of HYDRA and SHIELD having taken place many years ago, there's every chance Samuel Sterns has since gotten free, or perhaps imprisoned away in The Raft. If he had been tucked away in government custody all this time, that would be a clever way to explain his 14-year absence.
Currently, the illusive Intelligencia organization is attempting to steal She-Hulk's blood on her Disney+ show, seemingly with the goal to make more Hulks. As the same group has been formed by The Leader many times in the comics, there is every chance Sterns is behind the mystery going on in that show.
After all, Sterns already has an established history of studying Hulk blood in the MCU and he clearly had further ambitions to study it further. Perhaps that goal will be part of his endeavors in Captain America 4, especially since She-Hulk herself has been rumored to show up in the theatrical blockbuster.
Fans may be kept waiting almost two years to see The Leader return, this time in his fully mutated form, or there may well be a taste of what's to come for him by the end of She-Hulk: Attorney at Law. No matter the case, it's exciting to see one of the MCU's longest dangling threads finally being picked up years later.
Captain America: New World Order hits theaters on May 3, 2024.