His face twisted in surprise, shock and remorse. Surprise being for the fact that his arrogance led to his downfall. Shock that his cousin would end his life so easily, without a single thought. Finally, remorse for the fact that he would be leaving Harry again, in a more permanent manner. Each time he left Harry, it was due to a mistake on his part, he thought bitterly. He knew that this would be hard on Harry, hell, it would be hard on Remus as well. He felt as though all that he did was let Harry down.
The first instance that came to his mind was when he switched the role of secret keeper with Peter Pettigrew, the filthy rat. The second being conceding in in the argument with Rubeus Hagrid over Harry's custody the fateful Halloween in which Lily and James Potter were murdered in cold-blood by Voldemort. The third instance was allowing his pain and grief to take over, leading him to confront Pettigrew, only to be framed for his death and the deaths of 13 muggles. He missed out on 12 years of Harry's life. Now, after 2, he was leaving again. Life was cruel. Not only will Harry never know the warm embrace of his mother and gentle but reassuring squeezes from his father, he is losing his godfather as well.
The white light illuminated the room as the veil consumed him. Blinding as it was, it was beautiful in an almost disturbing way. How can such a bright light be something so dark? Sirius felt as if he had been falling for hours. Falling into what, he would like to know. Spinning in this world of nothing, he decided that he would take this all in stride. After all, what can a man that has already lost everything possibly have to lose?
The spinning came to an end as he finally neared his destination. Disoriented, he looked around the location. It was King's Cross station. As he took in the familiar surroundings, he heard someone clear their throat. Wary, he turns, only to face two people that he missed dearly. In front of him was the beautiful, vivacious Lily Potter and the love struck, caring prankster that is James Potter.
"You're about 40 years early, mate." James Potter stated, an eyebrow raised
"Never mind that James, he didn't go out of his way to come early" said the ever caring Lily
Lily captured Sirius in a hug that James had quickly joined. Each were in an emotional turmoil. None had considered the possibility of seeing eachother again. Each had grieved, all the while being mourned themselves. Over the years, they had been keeping an eye on their friends and their son, Harry, along with Harry's friends.
"It's a shame you got old, Padfoot" James stated, forever frozen at 21. At this, Sirius chuckled mirthlessly.
"It's a shame you didn't..."
Each sighed in regret. All three tormented themselves with the "what-if's" and the "if only's" Each felt guilt and sorrow at the childhood, or the lack thereof, Harry is experiencing. They can't change the past nor the present, they can only watch as it unfolds.