[ WP ] Write a time travel story that does n't create any paradoxes

Eric held the binoculars up to his bloodshot eyes. He had been outside of his childhood home since dusk, waiting for the intruder that killed his father and kidnapped his sister. He still has nightmares about it, although he has aged two decades since that night, this night. 
 
 The sound of the door being torn from it's hinges woke him up from a deep sleep. Still in a daze, he could make out the sounds of glass shattering and a scream. He ran downstairs, clutching his teddy bear, and found the sight that would haunt him forever. Eric's father was laying in the middle of the chaotic living room, barely alive, with his hand pressing tightly on his severely bleeding neck. 
 `` RUN! Get your sister out!'' Eric ran for his sisters room, but when he got there, little three year old Ashley was gone, only crumpled sheets, and a couple bloody handprints on the wall were left. The murderer had taken her out the window, and Ashley was never seen again. 
 
 It was time. He was going to get revenge. Eric walked up to the back door of his house. It was locked, but it did n't matter, he had his fathers old key that he kept around his neck. He silently slipped in, closed the door behind him, and hid in the shadows of the kitchen, with this head peeking into the living room toward the front door. He glanced at his watch. `` 12:06, Any second now''. 
 
 The refrigerator door closed. 
 
 Eric's eyes grew wide. He turned slowly to see his shirtless father, holding a slice of cold pizza, staring directly at him. Tears started to form in his eyes, he had n't seen his father's face in over twenty years. Before he could say anything, his old man landed a solid punch square in his jaw. Eric stumbled back, suddenly remembering that he did n't look like his eight year old self. He held up his hands as a show of surrender. `` Dad! It's m...'' His father ran, full speed and planted a shoulder in Eric's stomach, sending him careening into the front door, breaking it. After a few seconds of catching his breath, Eric stood up to see his father had crashed through the glass coffee table, and was struggling to breathe on the floor. He rushed over and looked closer. A shard of glass had punctured the jugular. With some poor judgement, his father had removed the glass and only caused himself to lose blood faster. `` Dad... no.'' Eric tried to put pressure on the wound, but was kicked off. His father still did n't recognize him. He suddenly realized what he had to do. 
 
 Eric ran around the corner to Ashley's room, as he heard little eight year old Eric coming down the stairs. He flung off her blankets and picked her up. He knew this is how it had to be. This is how it always was. But now he knew what was in store for his sister. She was going to go back to the future with him, and he was going to try his best to be as good of a father as the one they had both lost. 

