A-Next is the hip, new and younger version of the Avengers from Earth-982. The previous incarnation of Avengers were very much like their Earth-616 counterparts until they learned of a monumental threat from the reality of Earth-9907.
In this reality, the Nazis won World War II and the ruler of the entire world was Victor Von Doom (known to Earth-616 as Dr.Doom). He was on the verge of mastering a Universal Cube which would allow him to invade other realities. Earth-982's Avengers created a portal into Earth-9907 in which to stop Doom. The confronted their counterparts in that world known as the Thunder Guard, this universe's twisted version of the Avengers under Doom's control.
Many Avengers of Earth-928 perished during that battle with the Thunder Guard, but they did succeed in slowing down Doom's plan. One of the few survivors, Captain America stayed behind in Earth-9907 to lead the local resistance against Doom. Only six Avengers returned to earth: Hawkeye (Clint Barton) whom had been blinded in battle; Hercules,whom was driven mad by his experiences and had to be sealed in an adamantium prison; the Scarlet Witch; the Vision whom later became adviser to the U.S President; the Wasp who was distraught over the death of her husband Hank Pym; and Iron Man.
To prevent any further interaction with Earth-9906, Iron Man was forced to place the Scarlet Witch into a stasis field and used her powers to seal the rift. Shortly afterward, a weary Tony Stark decided that he could not longer continue as Iron Man and chose to retire.
Other heroes couldn't just sit by and let the Avengers fail apart and make no effort to fix the situation so several heroes like Jolt, Jubilee, Nova, Speedball, and the Steel Spider tried to continue the Avengers; however, it ultimately failed and the group finally disbanded. The Avengers Headquarters was turned into a Museum and was cared for by one-time Avengers' butler Edwin Jarvis. The Avengers were slowly turned into nothing more than a memory.
Ten years later, Kevin Masterson (son of the deceased Avenger Thunderstrike), came to the Avengers Headquarters to claim his father's mace, which had been left their by Thor for Kevin to inherit. Although the mace's magic appeared to be gone, the trickster Loki dispatched trolls to Earth to steal it from Kevin when he found it. Loki's presence triggered a dormant program left by Tony Stark. The program activated Mainframe, a sophisticated robot (much like the Vision) based on Iron Man's mind and designed to ensure that there would always be Avengers.
Mainframe sent out a signal to the Avengers; a call which was answered by the once disbanded team of Jubilee, Jolt, and Stinger; the daughter of Ant-Man (Scott Lang). The trolls' assault on Kevin was also witnessed by Speedball, and J2 (the son of Juggernaut), and six heroes came to Masterson's defense. Loki captured all six of them easily and brought them to Asgard while he tried to awaken the magic of the mighty mace. When he cast a spell, Kevin lunged at the mace which bonded the mace to him and granted him it's powers. Kevin freed the other heroes and defeated Loki and cast him into the darkness by summoning Thor who had succeeded his father Odin as the Lord, Master, and King of Asgard.
After the crisis, Mainframe suggested that they form a new team of Avengers. Speedball, Jolt and Jubilee declined full time service as Avengers; but Stinger, J2, and Kevin Masterson who assumed the identity of the new Thunderstrike agreed and formed A-Next.
Once more, Avengers Headquarters served as the base of Earth's Mightiest Heroes, but was simultaneously open as a public museum. The New Avengers me other new heroes such as: Earth Sentry (John Foster), son of the old Avengers associate Bill Foster, and Doc Magus, whom was the current Sorcerer Supreme. Mainframe later recruited American Dream and her dream team which included: The Crimson Curse, Bluestreak, and Freebooter. American Dream was cousin to Sharon Carter who has been an ally and romantic partner of Captain America. She modeled her whole persona behind Captain America's style and principles.
When Argo, the son of Hercules asked the Avengers to help find his father, the team located and found out where Stark had put him. They also learned why he was put there; his insanity. Jarvis was sought out for answers of why the first Avengers disbanded and he told them what little he knew. In their search for answers the team accidentally awoke the Scarlet Witch, placing their world in danger from the Universal Cube.
After coming to the realization of what happened to their predecessors they decided they had to set things straight and venture out into Earth-9907. The reunited with Captain America whom the helped overcome the Thunder Guard and succeed where the previous Avengers could not. In this battle the Crimson Curse seemingly lost her life destroying Doom and the cube and Thunderstrike became acquainted with Stormtrooper whom is an alternate version of his father and he chose to remain there and be with him.