Marvel's Agents of S.H.I.E.L.D. had seemingly put Hydra behind them, but the evil organization that once grew like a virus and took over S.H.I.E.L.D. keeps returning in one form or another. Hydra's history actually pre-dates the post-World War II creation of S.H.I.E.L.D. by thousands of years. The original cult of Hydra gathered in worship of the Inhuman called Hive and sought to return him to Earth from his banishment on the planet Maveth.
In the 20th century, the Red Skull created a version of Hydra as the scientific and research branch of the Third Reich. When the Nazis lost the Second World War, Hydra found new life within the newly created S.H.I.E.L.D. under the auspices of the defector Hydra scientist Arnim Zola. Hydra grew within S.H.I.E.L.D. for decades, recruiting sleeper agents including John Garrett, Agents Grant Ward and Jasper Sitwell, and World Security Council member Alexander Pierce. After the events of Captain America: The Winter Soldier, Hydra took over S.H.I.E.L.D. and dismantled the global spy network. By the conclusion of season 3 of Agents of S.H.I.E.L.D., Phil Coulson's team managed to destroy both Hive, who manifested in the body of Grant Ward, and the Hydra organization itself. However, Hydra won't stay dead.
This week's episode "Principia" brought back Werner Von Strucker, the son of one of Hydra's deceased leaders, Baron Von Strucker. Werner was once used as a pawn by Grant Ward and was later subjected to S.H.I.E.L.D.'s memory recall machine, which altered his mind and reduced him to a vegetative state. But Werner is now in the custody of General Hale. What's more, he has gained the ability of total recall of every aspect of his life. Werner's new ability is prized by Hale because she has plans to build "something new"... a team of some sort to combat S.H.I.E.L.D. and she needs Werner's memories to do it. Von Strucker finds himself recruited into Hale's plans to be part of a unit which thus far also consists of Hale's dangerous teenage daughter Ruby, and Carl Creel, the Absorbing Man.
Hale's grand scheme will be revealed in the March 30th episode "Rise and Shine", which also promises to bring back several prominent Hydra characters, including the deceased Jasper Sitwell, a younger version of Baron Von Strucker, and Daniel Whitehall, a long-lived Hydra leader who battled Agent Peggy Carter in World War II and was finally killed by Phil Coulson in season 2 of Agents of S.H.I.E.L.D. The episode is also poised to show the interactions a younger Hale had with Hydra's leaders.
While it's expected these major Hydra agents will be seen in flashbacks via Werner Von Strucker's memories, it also indicates that General Hale's ultimate plan is going to be influenced by Hydra's history and the actions of some of its most evil members. The preview for next week's episode "The Devil's Complex" even shows Leo Fitz confront the evil version of himself from the Framework who was one of the leaders of Hydra, thanks to a manifestation from the fear dimension. In the Framework's virtual reality, Hydra was the dominant force in the United States and controlled every aspect of life. Even though the Framework has been destroyed, there still seems to be no permanent escape from the specter of the evil organization continuing to haunt our heroes.
Whatever final form General Hale's government-sponsored superpowered team takes, the tentacles of Hydra continue to be a threat to Agents of S.H.I.E.L.D. long after its heads have been severed. Whether Hydra will return to prominence before the end of season 5 (and possibly the end of the series) remains to be seen, but fans could soon be hearing the familiar pledge of "Hail Hydra" once more.
Marvel's Agents of S.H.I.E.L.D. airs Fridays @ 9 pm on ABC.