Oliver Queen dies at the age of 83 from complications to pneumonia. He had survived knives to the gut, arrows to the back, bullets, shotguns and a couple other horrible near death experiences but in the end he died from something as simple as pneumonia.
Or so it seemed to the outside world.
The people closest to him, the ones that truly knew him, understood that the real Oliver Queen had died three months prior, from a broken heart.

February 26th 2065 was the day Oliver Queen lost the love of his life, his wife Felicity. It was also the day he gave up on life itself. A life without Felicity simply wasn't a life Oliver wanted to be a part of.
So, he had stopped eating and hoped he'd got to join his wife soon. But, apparently after having spend multiple years on a deserted island with low to no food at all, his body had no problem adjusting to the lesser calories it got to ingest. His children saw their father deteriorate but where powerless to stop it.

One night he heard Tommy and Olivia fighting in the kitchen.
"Tommy, you can see how bad dad has gotten. This has to end" he had heard his daughter say, the emotion clear in her voice.

"What do you want to do Ameel? Just let him die?" Tommy had asked, clearly not agreeing with this plan. His son had always been somewhat stubborn and hardheaded, Felicity used to joke that he got that from him.

"It's what he wants Tommy" Olivia says, always trying to be the voice of reason. So very much like her mother it hurt him to look at her sometimes.

Tommy swallows hard "But what about what WE want"

"Tommy," Olivia sighed "It's not about us"

Tommy swallowed again, his Adams apple bobbling up and down uncomfortably showing just how out of his element he was. "I can't," he sniffled "I can't lose him too"

Olivia took a step towards her brother, placing a delicate manicured hand on his shoulder. Her deftly yellow fingernails a sheer contrast on his black leather jacket "Tom, have you looked at him lately?" she sighed "he's already gone"

Tommy just stared into the distance blankly for the longest time and Olivia simply watched him. "We have to let him go, Tommy" she eventually says, coming to stand beside him.

"Do you know when we where little," Tommy says, catching her eyes "we were playing over there," he pointed to the rusted swing set in the backyard "and we overheard that conversation between mom and dad?"

Olivia sighed, remembering that particular conversation all too clearly. "Turns out mom was right," Tommy chuckled "like always".

Standing in the doorway looking at his two grown children he thinks back to the conversation they're revering to.
It had been right after he had come back from some other highly classified extremely dangerous mission with a broken arm and two more bullet holes. "You are going to be the death of me" Felicity had said the minute she wrapped her arms around him "If you're hurt, I'm hurt. If you die, I die"
She had told him in not so subtle wording that he wasn't allowed to die before she did.
Oliver manages to crack a little smile, his heart thumping loudly in his chest, at least that was one promise he did keep.

"Come on," Olivia smiled sadly "It's time"

Tommy raised an eyebrow "For what?" he asked.

"To say goodbye"

March first 2065 was the day they laid their mother to rest and exactly three months later, on June first, they buried their father right beside her. "Take care of each other up there" Olivia had said, before leaving the cemetery.

Tommy was the last one to leave, unable to separate from his father. They had always been really close, Oliver even teaching Tommy to shoot a bow and arrow, but that was as far is it went. As much as Tommy wanted Oliver refused to teach him any more than that, saying he never wanted his faith to become his own.
So, Thomas Robert Queen had grown up pretty normally, or as normal as possible when you're the son of Green Arrow and his super smart IT partner. He remembered when his sister was born. Olivia Moira Queen came into the world a spitting image of her father but with the wisdom and grace of her mother. At only five years old Tommy had vowed to be her greatest protector, and to this day he had kept this promise.

"I love you both" Tommy said, placing a hand on each of their stones "love each other up there like you did down here and everyone will die from envy" he chuckled. Pun intended.
Tommy suddenly felt a hand on his shoulder, turning around slowly he came face to face with his wife.
Sara had been his wife for over two decades now and he was still just as happy and in love as he was the first day they met.
His father once told him that when the right woman came along he would know, and know he did.
They had a good cry when he finally decided to introduce her to his parents. Turns out, Sara reminded them of one of their best friends, also named Sara, who died a long time ago at the hands of one of his father's worst enemies. "If you're happy, we're happy" his mother had said, before sharing a meaningful look with Oliver.

The relationship between his parents had always intrigued Tommy. The obvious mutual respect, the undoubtedly clear love, and the way they always knew what the other meant with just one single look. There was no doubt in his mind that the love between his parents was a love that went beyond what most people experienced in life. Oliver Queen and Felicity Smoak where soul mates and when she died she took his spirit with him.

Right now, looking at the two headstones next to each other, Tommy finally realizes something.
His father is finally back where he wanted to be. By Felicity's side. Right where he belonged.