HYDRA (Marvel Cinematic Universe)

HYDRA are the supporting antagonists of Captain America: The First Avenger, Captain America: The Winter Soldier and The Avengers: Age of Ultron. HYDRA is a terroist organization.

Captain America: The First Avenger
HYDRA appeared as the main group of villains in the movie Captain America: The First Avenger, and were led by Johann Schmidt, the Red Skull. They were stated as being part of the Nazi's deep science division, and they had tech that was superior to anything created at that time. Most of their tech was powered by the Cosmic Cube. Eventually Red Skull revealed plans to bomb various cities in the world, including Berlin. As such in the movie HYDRA has broken of from the Nazi Party and seek to replace them.

Captain America: The Winter Soldier
HYDRA returns in Captain America: The Winter Soldier with Alexander Pierce as their new leader. They plan to launch Project Insight which was thought to be done by SHIELD as a security enhanced project. But it was revealed by the consciousness of Arnim Zola through a supercomputer that HYDRA infiltrated SHIELD and that Project Insight is all a HYDRA plan to launch the three SHIELD Helicarriers and target over a million lives according to a special algorithm that Zola developed for HYDRA to follow. HYDRA is also revealed to have found Bucky in between films and brainwashed him to becoming the [http://villains.wikia.com/wiki/Winter_Soldier_(Marvel_Cinematic_Universe) Winter Soldier. ]At the end of the film HYDRA is now lead by Baron Wolfgang von Strucker and have captured Quicksilver and Scarlet Witch.

The Avengers: Age of Ultron
HYDRA returns again in The Avengers: Age of Ultron with their new leader Baron Wolfgang von Strucker. They plot to destroy the Avengers and possibly help Ultron take over planet earth.