Lonely (150)

Aligning the sights on the rifle was as natural as putting on her makeup. Allison was aware that she had one shot at the target, missing meant losing everything.

The thought made her smile; her existence was already void of meaning. Today she would correct it, the cause would be eliminated. Richard had taken everything she cared about, now she would take his life from him. The reason he lived was now a tall brunette with curves to challenge a racer, she had to be eliminated.

Richard would live an existence as lonely as Allison’s had been since he took the one person she loved most from her.

The word is lonely, this post is part of the FTP over at M3. The limit was 150 words, this post comes in at 108 words.
What did Richard take from Allison? Is the tall brunette the target of the rifle? Why does Allison only have a single shot?