Warnings: Blood, Angst, Major Character Death, Spoilers for Infinity War
Backstory: A twist on Infinity War.
Tony was dealing with trying to attack Thanos from a distance when Friday spoke.
"Sir, Peter Parker is attempting a stealth maneuver two hundred feet above you."
They were balanced on the portal, which was spinning slowly. T'Challa, Natasha, Cap, and Hulk were going after Thanos in close-range, Clint, Rhodey, Tony himself, and Thor were attacking him with swooping attacks, blasts of lightning, or arrows. Nothing really worked, not even the gunshots that announced the return of Bucky and the throwing knives that meant Loki was back. Shuri was injured, her leg mangled, and the Guardians were either in critical condition or unconscious somewhere on a ship. Last Tony had checked, Peter had been firing taser webs and web grenades at Thanos from a large distance.
"He is currently in a communication link with Shuri, Loki, Ned Leeds, and the Spiderling AI. I can attempt to hack in and allow you to listen to their conversation," Friday informed him.
"Do it," he commanded, firing his blasters at Thanos.
A moment of silence, then Friday spoke again. "I am unable to join their communication system. Peter has hacked into the Spiderling AI and improved her security immensely. If I am to enter their conversation, I will be detected and expelled from the system."
Tony swore and glanced up. He could see Peter steadily climbing higher, his dark Iron Spider suit blending into the portal.
Then Natasha was thrown past Tony, and he dove after her. He caught her, blasting immediately towards their ship.
"Peter is directly above Thanos. He is beginning to spin something out of webbing."
Tony made it back to the fight in time to see Loki snap on some sort of bracelet. It flared with a green glow and unfolded into an obviously vibranium arm-cannon.
Before anyone could do or say anything, Loki fired the cannon straight at Thanos. His gold helmet was blasted clear off, and it fell towards the ground.
Thanos roared and charged. Loki then released two throwing knives; one at Thanos, and one straight up.
Having ignored the second knife, Thanos dodged the blade and lunged towards Loki.
"Peter has caught the knife and is currently attaching it to his web structure. He has shut down communications between everyone except the Spiderling AI."
Tony was then distracted by Thanos getting thrown backward by a blast of lightning from above. Then he was firing his own blasters in an attempt to wear Thanos down.
Just as Thanos was slowly driven down, Tony heard a scream of pure anger.
Peter dove straight down towards Thanos, his waist wrapped in silk and a knife clutched in his hand. Just as Thanos looked up, it was too late.
Peter Parker drove the knife straight through Thanos' forehead, the silk stretched thin. He yanked the knife back out in a spray of blood as he was shot back into the air by his makeshift bungee-cord.
Until his silk snapped.
Suit eyes wide, Peter flailed, flinging the knife aside as he plummeted towards the spasming Thanos.
The Infinity Gauntlet slammed into Peter and somehow grabbed him. The teen screeched, fighting against Thanos' grip.
"I hope... you die..." Thanos choked, and flung Peter off the portal before the light died from his eyes.
"PETER!" Tony screeched, and dove after him.
Wind whistled past him. Eyes trained on the teen below, he ordered Friday to speed up his descent.
"Accelerated heart rate above his normal levels, increased intake of oxygen, no apparent injuries or harm sensed," Friday reported. "One thousand feet until impact with ground."
Tony gritted his teeth and the jets in his suit roared even louder. He became a red and gold blur blazing towards the ground. Below him, he spotted movements of cars and people as they moved about in the streets.
"Connecting to Peter's communication system at his request."
"MR. STARK!"
A sharp pang hit Tony's heart at Peter's voice. The teenager was crying, gasping for air as he flailed.
"Kid, it's gonna be okay, try and angle yourself to be parallel to the ground-"
"Mr. Stark, help me, please help me, I don't - I can't, help please help me!" Peter screamed, begged, even.
"Seventy-five hundred feet from impact."
People below had noticed them plummeting towards the ground. Enhanced cameras zoomed in, showing Tony that multiple people had begun filming with their phones, gasping as they spotted Iron Man and Spiderman in the air.
"Kid, breathe. I need you to breathe, and try to turn on your back so you can see the sky. Don't look at the ground, and spread your arms and legs out so you can slow yourself down," he directed softly, but firm enough to get Peter to react. "If you can do that, you'll be able to slow down enough that you can activate your web gliders."
Peter was still close to hyperventilating, but his flailing stopped. The teenager wiggled as his chest heaved, and managed to flip himself into his back. Tony was probably fifty feet above him, enough to see that his suit eyes were as wide as they could possibly go.
"Now, push your arms and legs out, like a starfish," Tony coaxed as Peter slowly stretched out his limbs. "I'm going to catch you, don't worry, it's going to be okay, Peter."
With gasping breaths, Peter stared up at Tony as they fell. "Mr. Stark, did- Thanos, he-he did something, my Spidey Sense- please, please, help me Mr. Stark, help me, please!"
"Five hundred feet from impact. You are fifteen feet from Peter," Friday told him.
One last blast of his suit, and Tony was below Peter.
Carefully, he swooped underneath the boy, cradling him in his arms. They were still falling, but Tony started accelerating upwards to slow their descent.
"One hundred feet from the ground."
Tony glanced down, and steered himself towards a more open part of a city block, which was coincidentally near where the former Avengers Tower was.
"Activating emergency landing gear," Friday spoke, and the remainder of their speed was canceled out as Tony landed.
He was cradling Peter in his arms, and carefully set him on the ground. After exiting his suit, Tony fell to the ground next to the young hero.
"Kid, kid, look at me," he said, lifting Peter's torso into his lap. "You're okay, it's gonna be okay. Friday says your vitals are normal, you're not hurt."
Every couple seconds, Peter would shiver violently, eyes wide. "Mr. Stark... n-no, my Spidey Sense, it's going crazy, help me, please," he begged.
People had begun to gather around them, keeping a good distance but still filming and taking photos. They were whispering, staring as Tony Stark cradled their city's hero, Spiderman, in his arms. Only now did they realize just how small he was compared to Tony.
"Okay, okay, you're gonna be alright, okay, Underöos?" Tony assured him. "You got him. You killed Thanos."
His mask moved as he must have grinned, then suddenly Peter's whole body stiffened. Before Tony could stop him, Peter's mask retracted. Peter jerked and rolled himself off of the man's lap, scrabbling on the pavement to get a few feet away. Then he was retching, and the contents of his stomach hit the ground.
Shocked, Tony reached out and rubbed Peter's back encouragingly.
Until he saw the blood.
Red splattered the ground, and sure, it was only a little, but it was enough to be concerning. Peter drew back, wiping his mouth, then collapsed backwards.
Barely managing to catch him, Tony cradled Peter's head. "Kid, listen, you're okay, it's probably just a cold or something, I've thrown up after fights before, and the altitude might've messed you up a bit-"
Opening his eyes, Peter groaned and mumbled, "it hurts, please, help me, Mr. Stark, please help me."
People were shocked, and now cameras were trained directly at the two heroes. They continued chattering, watching carefully.
"No, your healing can take care of it, don't worry," Tony assured him. "Friday's already run tests."
Peter coughed, and blood dripped from his lips. "N-no, it isn't- he did something, my healing is stopping it but it's not and it's not good," he wheezed.
As he watched, Tony ordered his suit to call the Avengers and their allies and to send them his location.
"Breathe, okay? You're okay, everyone's coming, they'll be here soon."
Peter's eyes were wide, and his chest was heaving as he panted. Panic flickered through his eyes, and he started shaking as tears gathered. "Mr. Stark, n-no, I can't- dust, I feel-"
Jets and engines announced the speedy arrival of most of the team, watching from nearby.
Choking on his words, Peter was gasping and openly sobbing. He clutched at Tony's shirt desperately. "Mr. Stark, it hurts, help me, please, help me!" His voice rose in volume until he was screaming, begging.
Tony took Peter's hands in his own, rubbing his thumbs over Peter's suit. He ordered the suit to retract the gloves, and squeezed Peter's bare hands. "Breathe, it's gonna be alright, Peter, breathe, it's okay, please, kid, c'mon."
Both of them were crying, clutching each other's hands.
Peter's voice suddenly rose even louder as he wailed in sudden pain. Tony gasped as the boy squeezed his hands even tighter. Biting his lip, Tony forced himself to squeeze back, noting that even through his pain Peter didn't hurt him.
Then he felt it.
Writhing in agony, Peter was screaming as the edge of his feet slowly dissolved into ash. The suit dissappeared as well and slowly, it moved up his feet.
Tony was in shock, trying to stay calm but ultimately failing.
"Peter, Peter, breathe, it's okay, I'm here, you're gonna be alright, breathe, don't worry, you're gonna- you're gonna be okay," Tony sobbed, one hand squeezed between Peter's hands. He ran his free hand through Peter's hair, and wiped away the boy's tears every few seconds.
Within three minutes, Peter's entire calves had turned to ash. He was no longer screaming instead hiccuping and crying quietly.
"PETER!"
Tony was distantly aware of Ned Leeds, Peter's best friend, rushing towards them. Neither hero acknowledged the teenager.
"That's Peter Parker!"
"Oh my god, he's dying-"
"Get help! Someone get help!"
People started screaming as they realized just who was under the mask of Spiderman.
Peter had disintegrated into dust up to his stomach now. He was shaking, clinging to Tony as the man rocked back and forth, both of them sobbing.
"I'm sorry, I'm sorry, Mr. Stark-" Peter gasped. He cried out as the bottom of his lungs began to turn to dust. Soon he was begging again.
"It's okay, kid, I'm sorry, Peter just breathe, I'm so sorry, just-" Tony choked out, until he felt it.
The tips of Peter's hands were beginning to blow away. Both heroes sobbed louder, Peter crying out for help. Tony lifted what remained of Peter to his chest, and the boy wrapped his arms tightly around the man.
"Please, help it hurts, dad, please help me oh my god it hurts make it stop PLEASE, DAD HELP ME!" Peter wailed, his grip loosening as his elbows turned to dust.
Tony rocked back and forth, tangling his hands in Peter's hair. "Breathe, it's okay, son just breathe, I'm here!"
Then Peter inhaled.
"PLEASE, DAD!"
And he was gone.
Sitting there with empty arms, dust coating his arms and chest, Tony couldn't move, couldn't react, couldn't think.
Because his kid was gone.
A/N: ANGST.
Okay, so this one I did after Infinity War came out, but before I saw it. Some assholes in one of my classes spoiled Peter's death and I screamed at them in the middle of class. Didn't get in trouble though haha. I then proceeded to do my interpretation on what I knew of Infinity War. This was actually written the day before I saw it.