Donna Noble always knew there was something missing from her life for a long time, she just didn't know what is was.
She lived her life with a carefree attitude, but she was longing to find that missing piece of her soul. She knew it was out there, somewhere, but where could it be?
Although Donna still had these thoughts frequently, she pushed them aside, so that they were invisible to the rest of the world. Little did she know that all of this time, she was being watched by a strange, bow-tied man with flyaway brown hair. Occasionally, she caught sight of him, but didn't think much about him.
But the man thought about her a lot. He knows her, and she knew him. "I bet deep down she still knows me." The man would think sometimes, but the truth stood; Donna Noble would never remember her best friend, her "stupid martian boy". And that pained the man more than anybody would ever know.
But the man saw everything that happened to her.
He saw her at her wedding day. Her fiery red was bursting out of the fields of white silk. She did look beautiful, and the man wished he could walk her down the aisle and hand her to her husband.
The man also saw Donna raise 2 children; a boy and a girl. The boy was a ginger, and the girl's name was Rose. "Why Rose?" Her husband had asked one day. "I don't know," she admitted, "I just like it."
The man saw her get hospitalized. There was no explanation. She just got sick, and they couldn't cure her.
That's when the strange man stepped into her life again. Donna Noble was older by then, 80 or 90 years old, perhaps. "Who are you?" she asked, a hint of her old sassiness in her voice. The man put a hand on her cheek, and a flood of memories filled her mind.
She saved planets and galaxies with this man with this man. This man was her best friends. She yelled at him for everything, but she still loved him to bits. She helped this man reunite with his lover, Rose. And she lost this man, she lost her best friend.
T
hat's what she had been missing her whole life. She was missing her best friend and she didn't even know it. And now that Donna Noble knew the answer to her life-long question, it was too late.
The Doctor kissed his best friend's hand and let her go. The most important girl in the world smiled, and faded into the comforting arms of death.
But the man in the bowtie would never join her.