On the presentation balcony of Earth-1193's version of Westminster Castle, the Queen announces the betrothal of her son Prince William, Prince of Wales, to Princess Katherine. A crowd is assembled in front of the castle and the announcement is celebrated throughout the entire realm. Excalibur and Alistaire Stuart join the royal family on the balcony. All of them are dressed into appropriate clothes while Stuart is taking pictures of the event. Then, the royal family and their guests join the party inside the castle where people are dancing and talking about the recent events. People are especially interested in Captain Britain who is a national hero of the realm while Meggan (Earth-616) announces that she wants to dance. Kitty Pryde realizes that Meggan prefers to dance with Nightcrawler. Alistaire and Rachel Summers join the dance while Captain Britain is surrounded by his fans. The Ogre who captured Kitty and Katherine before became a butler in the castle and offers Brian a drink, together with his apology. Misjudging his own powers, he then pushes Brian into the buffet.
Meggan, who is dancing with Nightcrawler, adjusts her outer appearance to him, jealously watched by Captain Britain. Nightcrawler, on the other hand, realizes that Kitty is jealous of Rachel Summers who is still dancing with Alistaire Stuart. Feeling lonely and ugly - compared to Rachel - Kitty leaves the party together with Lockheed, phases through the castle wall and returns to the Excalibur Train. The train was repaired and equipped with exquisite furniture. When Kitty enters the train, she discovers Widget who is eating the equipment. She shouts at him and he answers her for the first time, asking them about their names. Kitty introduces herself and Lockheed and then feeds the garbage to the hungry Widget. They are disturbed by loud voices and noises outside the train: Excalibur returns after a clash between Rachel and Sir Nigel, Nigel Frobisher's counterpart in this dimension. He has some obscene thoughts about Rachel and she takes revenge by taring and feathering him. Brian tells her to behave because Excalibur is a guest in this realm, but when she telepathically informs him about Sir Nigels thoughts, he becomes angry and wants to teach him proper manners. Nightcrawler tries to calm his teammates down, but is interrupted by Widget who starts to draw energy from Rachel. She can't stop him and Widget becomes a glowing ball, full of Phoenix energy. Suddenly, the train and all its passengers disappears.
Moments later, the train crashes into the ground again, this time in a region at the English coast. The Excalibur members identify the Excalibur Lighthouse, believing that they finally returned home to their dimension. However, something seems to be very odd; Kitty discovers that the tide is much lower than it used to be. In addition, the ground starts to shake and then a tsunami threatens the coast. It's too late to run for cover, so Rachel protects her companions by creating cocoons for each of them. The wave hits their position and the cocoons are swept away. When the water leaves, all cocoons lay in the grass besides their train. The trapped heroes free themselves and examine the damage that was done to the train. The train seems to be intact and even remained dry inside, but one cocoon is missing - Rachel's. Suddenly, a young man appears, introducing himself als Rick Jones, Avenger. He explains that Excalibur was considered missing in action for one week now. He also states that he likes Captain Britain's new costume. He then offers them to take them to the Avenger's Headquarter with the Quinjet because they took the cocoon to New York in order to examine it. Kitty asks Lockheed to stay with the train and guard it and then Excalibur and Stuart get on board of the Quinjet.
After a short while, they hit a yellow wall which seems to extend from the ground up above the atmosphere. Jones takes the Quinjet out into space and the passengers discover that the wall is in fact a leg - the leg of a titanic version of Hank Pym. Hank Pym explains that he experimented with supergrowing powers but the experiment got out of control. Now he is a titan and every move he makes and every breath he takes triggers disasters on Earth. Suddenly, Namor McKenzie jumps at him and shoots with a super weapon, seeking revenge for the destruction of Atlantis. The giant falls into the ocean, triggering an enormous flood wave. Captain Britain rescues the drowning Quinjet and takes them all to New York. There, various superheroes seem to be fighting each other in the ruins of the city. A strange demonic version of Captain America explains to them that all superheroes are caught up in "Acts of Vengeance" and leaves in order to join the fighting after Jones asked him if he needed a sidekick. Excalibur realizes that this isn't their own dimension but another alternate reality. They decide to split up, to search for Rachel and to leave the madhouse as soon as possible. Stuart and Kitty visit the Baxter Building to consult the Fantastic Four. A secretary asks them to draw a number and Alistaire draws a 10, followed by 23 zeroes - their place in the queue of super heroes who are demanding an audience with the Fantastic Four.
Uptown, Captain Britain and Rick Jones get caught in epic battles between alternate versions of Iron Man, Thor and Loki. Suddenly, Brian is attacked by the Hulk, but he knocks him down. Jones is shocked that Brian beats a person with the mind of a baby and tries to comfort the crying Hulk. Disgusted about the events, Captain Britain leaves the scene and flies away.
At Damage Coordination Headquarters, Kurt and Meggan meet various alternate superhero versions. Mysterio advises them to wear their original customs in order to be recognized as super heroes - and not the old-fashioned gowns they got in the royal castle. Nightcrawler and Meggan change into costumes. They ask Mysterio about the missing cocoon, but he explains that it isn't stored in the Department. He sends them upstairs to "lost property". The madness that surrounds them becomes worse every minute and they meet multiple versions of Wolverine in various costumes who are studying lines for a Wolverine casting. At "lost properties", they must learn that they are in the middle of a cataclysmic cosmic cross-continuity caper. Nightcrawler and Meggan decide to leave, not understanding a word of the explanation. Together with Brian, they join Kitty and Alistaire who are still waiting in the queue at the Baxter Building.
Excalibur doesn't know that the Fantastic Four (or their alternate counterparts with switched powers) already examine Rachel's cocoon. Before Reed Richards finds out how to open it, Rachel breaks free by using her Phoenix power, disrupting the upper floors of the Baxter Building. The F4 promise to help Rachel, but before they can finish their conversation, Galactus appears above them. He announces that this dimension must be destroyed because it is a danger to all other realities. He then destroys the world - and in the nick of time, Widget draws Phoenix's powers and transports Excalibur into another reality.
Standing on the moon, Galactus watches the dead, barren rock - formerly called Earth - and worries about the dangers of the Phoenix powers. He warns the causer of the chaos who is also sitting on the moon not to repeat this chaotic event. Once Galactus left with his spacecraft, the causer snips and revives Earth, where all superheroes continue fighting each other.