Succeeding in acquiring the Super Soldier Serum, Karpov oversaw the creation of the Winter Soldiers, an elite group of five HYDRA assassins infused with the serum. However, the Winter Soldiers, except for Barnes, lost control and started a riot, resulting in all of them being put under deep sleep in Cryostasis Chambers.
Twenty-five years later, the former Sokovian special forces Colonel Helmut Zemo arrived at Karpov's house in Cleveland, Ohio. There, Zemo attacked him and knocked him out. He then tied up the HYDRA agent and placed him upside down and partially submerged Karpov's head in a sink. Zemo then started filling the sink with tap water to extract the 1991 mission report from him.
However, Karpov refused to talk, so Zemo took the book with the trigger words to operate Barnes and abandoned him. Heavily restrained and unable to lift his head from the water, Karpov spoke the HYDRA oath before drowning in the overflowing sink.
Zemo framed the Winter Soldier for a attack on the Vienna International Centre the day the Sokovia Accords were being signed. After a high-speed chase, Barnes was taken to the custody of the Joint Counter Terrorist Centre. Meanwhile, Zemo kidnapped and murdered Theo Broussard and took his place as the unfortunate psychiatrist. Also, Zemo had also sent an EMP bomb to the city's main power plant.
Zemo gave a psychological evaluation on Barnes, acting that nothing was amiss, until the EMP bomb detonated, cutting out all of the building's power, including the security cameras. Using the book, Zemo reactivated Barnes' program. Barnes gave him all information about his mission and the Winter Soldier Program and Zemo arrived to the HYDRA Siberian Facility.