Captain America and the Avengers are trying to use a machine to pierce the dimensional barrier between their world and that of Arkon, to rescue Scarlet Witch and some scientists, and to prevent Arkon from igniting a nuclear holocaust on Earth to provide power for his own world. Quicksilver is impatient with the fact that the Avengers can't get a power supply stable and powerful enough. But Cap has an idea.
Meanwhile Clint Barton, who upgraded from Hawkeye to Goliath in #63, is combining his identities by practising with a giant crossbow. He is interrupted by his lover Black Widow, who abruptly tells him she is leaving him.
Meanwhile on Arkon's world, the barbarian ruler woos Wanda even as his scientists extract the secrets of atomic bombs from the captured Earth scientists. He lies to her, claiming that they have found a way of supplying their world with power without destroying the Earth. But he still won't let her return home, because he wants her for his queen.
At that moment the assembled Avengers arrive, including Iron Man and Thor. Thor's hammer had provided the power to get them here. They fight their way through an army to get to Arkon. Instead of the yellow 'lightning bolts' he used last issue to transport people to his world, Arkon now uses red ones as explosive weapons.
The battle goes against Arkon's forces. But he uses a yellow bolt to take himself and Scarlet Witch to Earth to the top of the Empire State Building. Thor sends the Avengers and Quicksilver back after him. They fight, and Arkon defeats each one. But this is only a delaying tactic while his scientists prepare to destroy the Earth.
But then Arkon gets a message from his Vizier. Cap, Iron Man and Thor stayed behind. Iron Man has built a device to re-energise the light-giving ring that encircles Arkon's planet. And Thor powered it up with his hammer. So there is no need to destroy Earth.
Arkon leaves, but not without informing Scarlet Witch that crossing the dimensional barrier has kick-started her hex power. He says he no longer wishes to force her to marry him, but may return someday to ask her. And it seems Wanda may not be averse to the idea.