Age of Ultron

"Age of Ultron" is a crossover event featuring episodes of the live-action television series Iron Man, Thor, and Captain America on NBC. The crossover began on May 24, 2016, with Iron Man, continued on Thor on May 25, and concluded on May 26 with Captain America. In "Age of Ultron", the Avengers have been reunited to thwart Hydra, but face a much bigger threat with the arrival of the artificial intelligance Ultron. Development for a second crossover began directly after the huge success of the previous crossover, Avengers Assemble. The premise and title of the crossover were revealed in March 2016 as production on the episodes began.

Plot
In the Eastern European country of Sokovia, the Avengers—Tony Stark, Steve Rogers, Thor, Bruce Banner, Natasha Romanoff, and Clint Barton—raid a Hydra facility commanded by Baron Wolfgang von Strucker, who has been experimenting on humans using the scepter previously wielded by Loki. They encounter two of Strucker's test subjects—twins Pietro, who has superhuman speed, and Wanda Maximoff, who has telepathic and telekinetic abilities—and apprehend Strucker, while Stark retrieves Loki's scepter. Stark and Banner discover an artificial intelligence within the scepter's gem, and secretly decide to use it to complete Stark's "Ultron" global defense program. The unexpectedly sentient Ultron, believing he must eradicate humanity to save Earth, eliminates Stark's A.I. J.A.R.V.I.S. and attacks the Avengers at their headquarters. Escaping with the scepter, Ultron uses the resources in Strucker's Sokovia base to upgrade his rudimentary body and build an army of robot drones. Having killed Strucker, he recruits the Maximoffs, who hold Stark responsible for their parents' deaths by his company's weapons, and goes to the base of arms dealer Ulysses Klaue in Johannesburg to obtain Wakandan vibranium.

The Avengers attack Ultron and the Maximoffs, but Wanda subdues them with haunting visions, causing Banner to turn into the Hulk and rampage until Stark stops him with his anti-Hulk armor. A worldwide backlash over the resulting destruction, and the fears Wanda's hallucinations incited, send the team into hiding at a safe house. Thor departs to consult with Dr. Erik Selvig on the apocalyptic future he saw in his hallucination, while Nick Fury arrives and encourages the team to form a plan to stop Ultron. In Seoul, Ultron uses Loki's scepter to enslave the team's friend Dr. Helen Cho. They use her synthetic-tissue technology, vibranium, and the scepter's gem to craft a new body. As Ultron uploads himself into the body, Wanda is able to read his mind; discovering his plan for human extinction, the Maximoffs turn against Ultron. Rogers, Romanoff, and Barton find Ultron and retrieve the synthetic body, but Ultron captures Romanoff. The Avengers fight amongst themselves when Stark and Banner secretly upload J.A.R.V.I.S.—who is still operational after hiding from Ultron inside the Internet—into the synthetic body. Thor returns to help activate the body, explaining based on his vision that the gem on its brow is the Mind Stone, one of the six Infinity Stones, the most powerful objects in existence.

This "Vision" and the Maximoffs accompany the Avengers to Sokovia, where Ultron has used the remaining vibranium to build a machine to lift a large part of the capital city skyward, intending to crash it into the ground to cause global extinction. Banner rescues Romanoff, who awakens the Hulk for the battle. The Avengers fight Ultron's army while Fury arrives in a Helicarrier with Maria Hill, James Rhodes and S.H.I.E.L.D. agents to evacuate civilians. Pietro dies when he shields Barton from gunfire, and a vengeful Wanda abandons her post to destroy Ultron's primary body, which allows one of his drones to activate the machine. The city plummets, but Stark and Thor overload the machine and shatter the landmass. In the aftermath, the Hulk, unwilling to endanger Romanoff by being with her, departs in a Quinjet, while Vision confronts and seemingly destroys Ultron's last remaining body. Later, with the Avengers having established a new base run by Fury, Hill, Cho, and Selvig, Thor returns to Asgard to learn more about the forces he suspects have manipulated recent events. As Stark leaves and Barton retires, Rogers and Romanoff prepare to train new Avengers: Rhodes, Vision, Sam Wilson, and Wanda.

Iron Man

 * Thomas Kretschmann as Wolfgang von Strucker
 * Henry Goodman as Dr. List
 * Andy Serkis as Ulysses Klaue

Thor

 * Keira Knightley as Peggy Carter
 * Julie Delpy as Madam B
 * Linda Cardellini as Laura Barton

Captain America

 * Kerry Condon as F.R.I.D.A.Y.

Development
After the immense success that was "Avengers Assemble", NBC allowed Kevin Feige full control over the visions of each series (Captain America, Iron Man, and Thor) for the 2015–16 television season. Feige began plotting out a second crossover by June 2015, when development of the series' upcoming seasons began. Despite the announcement of Guardians of the Galaxy in August, Feige confirmed that it would not be involved in the crossover. In March 2016, the premise and title of "Age of Ultron" were revealed, along with the casting of Wanda and Pietro Maximoff, and Ultron.

Writing
Though Feige developed the story for the crossover and oversaw the writing of each episode, Joss Whedon returned to write the crossover, with Thor also overseen by showrunner Christopher Yost, and Captain America by showrunners Anthony and Joe Russo. After being cast in mystery roles for an episode in Captain America, Adelaide Kane and Thomas Mann were revealed to be portraying Wanda and Pietro Maximoff in the crossover, along with James Spader's casting as Ultron. Feige and Whedon also stated that they attempted to make each episode of the respective series feel more like true episodes of those series than the previous year.

Filming
Filming once again took place in New York City from March 18 to April 6, 2016. Joss Whedon directed all three episodes.

Marketing
Marketing for the crossover began in April 2016, with promotional posters for each character released. Several teasers were released throughout the month as well, before a full-length trailer was unveiled on May 5, 2016.

Broadcast
The crossover began on May 24, 2016, with Iron Man, continued on Thor on May 25, and concluded on May 26 with Captain America. Though Thor aired on Thursdays at 8 pm throughout 2016, it moved to Wednesday at 10 pm, Captain America's usual slot, due to the middle episode having more to do with Thor, and the final episode having more Captain America characters. The Captain America episode also led into the finale of Guardians of the Galaxy, which boosted its ratings as well.

Critical response
About the crossover as a whole, many praised the acting, visual effects, new characters, and villain, while also criticizing the pacing, Whedon's attempt to fit so much into three episodes, as well as the inability to live up to "Avengers Assemble". On an episode-by-episode basis, IGN gave the crossover an overall "Great" score of 8.6/10, with Iron Man receiving an 9.2, Thor receiving a 7.5, and Captain America receiving a 9.1.