Tony Stark knows that if it came to a blow-for-blow battle, it’s not one he’s likely to win.  Steve Rogers is as accomplished a fighter that there is, and even with the technological advantage that Stark has, Captain America is not someone to be underestimated.  So, far from Cap’s reach, Stark scours the city from the clouds, searching for any trace of his fellow Avenger.

Hours pass by, and still nothing; Stark’s fuel cells are beginning run low so he decides to head back to Stark tower, reboot, and then continue the search.  But upon his arrival he senses that something is off.  The power is out, and the entire building seems deserted.

“Jarvis?”  He asks, peeling off his helmet.  “Jarvis…where are you?”

“I’m afraid Jarvis won’t be joining us this evening.” Cap says from the shadows. “You know, we’ve butted heads over the years, but more often than not we shelved our differences and fought the good fight.”  He says casually, coming forward he sits on the edge of Stark’s desk, vibranium shield in hand.  “But now there’s only you and me, Tony…you’re the smart one; tell me how it’s going to end.”

Mirroring Cap’s laid back approach and candour, Stark replies “Well, first I figured I’d blast you with my repulsors, and, assuming you’d dodge those I’d power up my uni-beam and level this entire floor, bringing the rest of the tower down on your head.”

“Oh?  That seems grandiose, even for you.”  Rogers says, twirling a pen he found. “There’s only one problem with your strategy.”
 
“Really?  And what’s that?” Stark wonders.

“This.” Cap says with an outstretched hand, showing Tony his secret weapon: a modified EMP Tony had created as a failsafe should his armour malfunction or should the armour fall into the wrong hands.

Stark stumbles backward, panic sets in, what can he do without his armour?

“I’m sorry Tony” Cap says without emotion.  He presses the device and Stark’s armour begins to shut down, he falls to his knees as the hydraulic system dies.  Rogers lunges forward; hurling his shield he strikes Ironman in the chest, cracking the plating, exposing his vulnerable torso.  Stark rolls away avoiding a devastating knee; he scrambles towards his desk flipping chairs and tables in his wake in a vain attempt to slow Captain America down.  Out of breath, Tony cowers behind his office chair.

“Come on now Tony,” Rogers chides “dying in battle is an honourable way to go.  At least go with dignity.”

“Well, you must not know me as well as you think” Stark replies, “I’m going down kicking and screaming.”  So with a smile on his face he barks “Emergency Evac. 1, Authority: Stark, Tony” and a hatch beneath his chair opens up and he falls from sight.

Captain America is left alone in the office with a gaping hole in the floor where Tony used to be.  Briefly, he surveys the scene then  decides to follow, diving head first down the escape tube.  He careens of the sides and yet gracefully comes to rest at the bottom, inside Tony’s workshop.

“I’m glad you could make it Steve,” says Tony, the sounds echoing around the warehouse.  “Though it looks to me like the tables have turned.”  His War Machine armour powers up; striding effortlessly towards his opponent Stark fires a barrage of anti-personnel missiles and flurry of machine gun fire at Cap. 

Instinctively, Captain America dodges, deflects, and advances. Always pressing forward, Cap closes the distance quickly but Stark’s firepower keeps him out of arms reach.  For what seems like an eternity, he bounces around the workshop until finally Stark is out of bullets.  Rogers sees his chance and attacks.  He jumps in the air, his shield raised over his head; with all his strength brings his iconic weapon down on Ironman’s head.  The helmet splits in two and falls away, Stark staggers back from the blow and falls to his back, Captain America standing on his chest.

Looking down at his adversary Cap praises his effort, “I’m impressed Tony, in the end you put up quite a fight.”

“But you know the funny thing Cap?”  Stark retorts, “Remember my strategy about bringing the tower down on your head?…That’s still in play.”  Before the words are even out of his mouth, his chest plate lights up and the devastating uni-beam purrs to life.  True to his word, Ironman unleashes the full potential of his battle-suit.  Cap rolls away as the workshop is filled with intense heat and light, the uni-beam blasts upward through Stark tower, shattering concrete and melting steel.  The energy stream fires through the roof, illuminating the night sky, causing the tower to pancake in on itself.  Crashing down level by level, the two combatants look at each other while the workshop creaks and groans.

“I guess I should’ve said that I was sorry” Stark chimes; it is the last thing Cap hears as a mountain of rock and metal collapses down on top of them.

When the dust settles Ironman rises from the rubble, his broken comrade in hand.  Captain America is dead.