Falcon And Winter Soldier - Everything You Need To Know About Zemo
2. He Worked With Captain America
In Captain America: Steve Rogers #7-11, the Red Skull endowed the Cosmic Cube with the ideals of Hydra. The artefact came into contact with Captain America, implanting him with false memories that convinced him he had been serving Hydra since World War II.
The Cube also convinced him that Helmut Zemo had been his best friend ever since he defended Steve Rogers from bullies when they were teenagers. Because Zemo was suffering amnesia in the modern era, he believed Cap when he told him they had been friends for decades. As a result, Zemo promised to help Cap any way he could to restore Hydra to its former glory.
Ironically, instilling the memory of Cap and Zemo being the best of mates was the Red Skull's undoing. When Cap's nemesis ordered the star-spangled avenger to assassinate his oldest friend, he refused. Believing Skull had lost his way, Captain America faked Zemo's murder to lull his master into a false sense of security. When the Red Skull was at his weakest, Cap killed his master and declared himself the leader of Hydra.