This issue is the finale of the
Crossing crossover in
Avengers,
Force Works,
Iron Man and
War Machine, along with one-shots
Avengers: The Crossing and
Avengers: Timeslide. It follows directly from Iron Man v1 #325.
Kang has been controlling
Iron Man for a long time, amongst other things making him build a
Temporal Transposer, and kill people to hide his activities.
The
Avengers have been back through time to recruit a teenage version of
Tony Stark from an alternate timeline, to decipher Iron Man's machinery. He is protected by a spare set of Iron Man armour, but Iron Man ripped his heart out.
The action of this issue takes place in Iron Man's secret Arctic bunker, which transforms into Kang's citadel as Kang takes it out of time with the Temporal Transposer. Kang fears someone whose arrival is imminent (possibly
Onslaught). He intends to build an army of
Anachronauts outside of time, to return when he is ready to confront this opponent.
Crystal keeps young Tony Stark in cryogenic suspension while the other Avengers (
Black Widow,
Captain America,
Giant-Man (
Hank Pym),
Hercules,
Quicksilver,
Vision and
Wasp (mutated into an insectoid form)) plus
Century (of Force Works),
Hawkeye (technically not a member at this point) and
Masque (later revealed to be a clone of Madame Masque) fight Kang,
Mantis,
Malachi,
Tobias and the Anachronauts.
Mantis tells Vision she joined Kang for revenge on him, for spurning her for Scarlet Witch, driving her to marry the
Cotati Swordsman and to give birth to the
Celestial Messiah. She says they have used someone he cares about (Iron Man), and others he doesn't recognise (hinting that Malachi and Tobias are his and Scarlet Witch's sons, long thought dead).
Kang says that his plan has been brewing for a long time. He first tried to bend Hank Pym to his cause, causing his many mental problems (meaning he began before Avengers v1 #59). Then he moved on to Iron Man (time unspecified, but possibly before the alcoholism of Iron Man v1 #120).
Iron Man shakes off the influence of Kang, and rescues the Cotati Swordsman. The Cotati Swordsman and the Avengers try to bring Mantis back to the side of good, but she kills (?) him. Iron Man destroys the Temporal Transposer but is fatally wounded.
Kang and Mantis abandon the now-useless citadel, and the Avengers find themselves in the Agaphaur temple of the Priests of Pama in Vietnam. Before he dies Iron Man passes on the schematics of his chestplate, to keep young Tony Stark alive.
Tuc brings Crystal and Quicksilver's daughter
Luna back from where he has been keeping her safe. He makes a cryptic comment that Crystal should be able to guess who he is (a list of current Avengers characters at the back of
Avengers Unplugged #2 says he is a future son of Crystal). He takes away the Cotati Swordsman's body.
Scarlet Witch (of Force Works) arrives in a hex-ship looking for them. The fate of young Tony Stark begins in an epilogue to the Crossing in one-shot
Iron Man: Age of Innocence.
Although this is the final issue of the Crossing proper, it continues with some epilogues starting with
AGE OF INNOCENCE: THE REBIRTH OF IRON MAN.
Give that special marvelite a timely gift