In Season Three, Ultron returns after his apparent demise and seeks revenge on the Avengers. The Avengers must defeat him as well as new threats like Baron Zemo's Masters of Evil and Kang the Conqueror. Vision, Black Panther, Captain Marvel, Ms. Marvel, and the Inhumans will also be appearing this season.
The Avengers learn what it's like to work as a team again as they battle AIM's latest weapon - a new and improved Super Adaptoid developed by the Scientist Supreme!
Ultron is back and plans to replace humanity with robots known as Ultimates.
Captain America battles to rescue Bucky who has been captured by Baron Zemo.
Hawkeye must defend the Avengers Tower from Baron Zemo who has taken the Masters of Evil members Beetle, Fixer, Goliath, Moonstone, and Screaming Mimi under his leadership.
The Avengers fight to stop Justin Hammer's new weapons factories, but are both helped and hindered by a mysterious new team of heroes known as the Thunderbolts.
When the Avengers discover that the Thunderbolts are actually the Masters of Evil, they must decide whether they can trust the villainous team to turn on their leader, Baron Zemo.
Dr. Strange needs the Avengers' help when Dormammu steals the Eye of Agamotto.
Hulk is drained of his gamma radiation and is stuck as Bruce Banner.
When townspeople transform into primitive creatures, the Avengers attempt to help them by putting themselves into conflict with the Inhumans.
The Avengers must team up with the Inhumans to stop their old foe, Ultron, who plans to unleash a dangerous weapon upon Earth.
Captain America and Iron Man join forces with Inferno and Ms. Marvel to stop another Inhuman, The Ghost, from stealing Friday.
The Avengers try to stop A.I.M. from stealing high-tech weapons from the future ever since it was discovered that they upgraded the gear of Whiplash and Spymaster. Their fight with A.I.M. attracts the attention of the 30th-century warlord Kang the Conqueror since it was his technology that A.I.M. used as he takes control of the A.I.M. Agents present.
With the exception of Thor, the Avengers become trapped in the 30th century and must beat Kang the Conqueror to find their way back to their own time.
Black Widow comes face-to-face with Yelena Belova, who in her determination to create the ultimate weapon turns Hulk into the Winter Hulk.
Thor teaches the Vision the value of friendship by taking him to Asgard where together they must fight an Ultron-controlled Destroyer.
The Avengers join Captain Marvel in a fight to stop a powerful sentient spaceship from destroying Earth.
Despite their differences, the Avengers team up with Black Panther in order to stop the evil Klaue.
On the set of a superhero movie, the Avengers team up with Ant-Man to stop the madman Egghead from destroying Los Angeles.
Baron Zemo returns to target the Avengers alongside his father, whom he's brought back from the 1940s.
The President has signed the New Powers Act in response to the Terrigen Fog creating new Inhumans and Truman Marsh is assigned to be the Avengers liaison to the government. Meanwhile, scientists backed by HYDRA enter a gamma storm with a stolen spaceship and are transformed into the U-Foes where they plan to take over HYDRA when Baron Strucker hasn't returned.
Following Truman Marsh replacing Hulk with Red Hulk, the Avengers must stop Leader from building and unleashing his secret weapon.
The Avengers must stop an out-of-control Red Hulk as he threatens to destroy an entire town.
The Avengers must stop Maximus from wreaking havoc in Attilan and causing its citizens to lose control of their powers. At the same time, the Inhuman Registration Act is passed where the Avengers have their own opinion on that.
With the Avengers disassociated with the government amongst the Inhuman Registration Act, Truman Marsh assembles The Mighty Avengers (consisting of Ant-Man, Black Panther, Captain Marvel, Ms. Marvel, Red Hulk, Songbird, and Vision) to take their place where they first fight against Baron Strucker and HYDRA with the Avengers after them. Later on, the Avengers work to keep the Mighty Avengers from taking the Inhumans Haechi, Flint, and Iso into custody.
After being detained, Iron Man works to free the Avengers with help from Black Widow, When the Inhumans are mind-controlled into attacking innocent humans, the Avengers must find a way to override their control and end the war.
The Avengers, old and new, must find a way to free the Inhumans and the world from Ultron’s control. When Ultron takes control of Iron Man, Doctor Strange comes up with a plan that might result in Iron Man's sacrifice.