This is a synopsis by T Vernon. An earlier synopsis by Kevin Hollander is lurking below Elektra.
Pepper Potts is working the desk at Stark Solutions when Happy Hogan enters and they are surprised to see each other, each hired by Tony Stark since he didn't know they are no longer together....
Tony is off on a skiing trip to the Swiss Alps to meet with the first client for his new firm, Countess Stephanie de la Spirosa; they are getting along despite her having hired the Mad Thinker to uncover Iron Man's identity in a fit of pique. Stephanie has a lot of social activities planned but she is disappointed that Tony just wants to work on the problem she hired him to solve, namely irregularities in the accounting at the company her late husband left her. That night as Iron Man he checks out the Dufours Manufacturing Corps' plant and discovers there is a huge hidden chamber carved into the mountain behind it. He enters by a hidden hatch and discovers a secret facility for manufacturing weapons. Iron Man is caught by guards with powerful energy weapons and crashes out into the sky above where he is met by the Siege Engineers, armed guards on sky-cycles; he leads them through the mountain until he reaches the best place to trigger an avalanche, burying them temporarily as he escapes....
The next morning Tony meets Stephanie at breakfast where she is accompanied by two sinister bodyguards. He tells her that he has figured out that the job offer was a phony and what she really wanted was Iron Man. The two bodyguards who were actually keeping her prisoner prepare to kill them both but Tony sets off explosives he had placed outside the night before and fights his way past them while they are distracted. He dons the armor and again Iron Man faces the Siege Engineers and this time he's ready for them....
The Mandarin receives word that his Swiss supplier has been compromised and that Tony Stark and Iron Man are involved. He gives the order that everyone shall die....
Iron Man is met by a huge flying gunship which hovers menacingly above him but suddenly the chalet where he and Stephanie were staying is blown to bits by a particle beam—and suddenly he is facing a trio of Dreadnoughts, deadly robots that reveal they have killed Tony and Stephanie and now will deal with everyone else....