She had only seen the spell once, when she had borrowed a sixth year book when her own had gone suspiciously missing. Alicia hadn't thought much of it, not knowing whether it would work or not, nor its purpose. She didn't know why, but it stuck with her, always at the back of her mind.
Alicia had thought she had forgotten the spell, lost somewhere at the back of her memory with thousands of other things, when thoughts of it hadn't resurfaced for years.
The blood of the Battle of Hogwarts somehow brought it back, reminding her of its presence until "Sectumsempra" had left her lips without a conscious thought.
The resulting fountain of blood was unforgettable as it drenched her like rain. It wasn't only one person's, she could tell, because there was suddenly a wall of people that was falling towards her. Alicia was only barely able to roll out of the way in time to avoid it.
There was little doubt that they were dead. There was too much blood.
Alicia wanted to curl into a ball and cry. She hadn't meant to kill them, just stun them or keep them unconscious for a while. They had friends, family, maybe even children! And she had taken them away from those people.
She felt terrible, but she also knew that if she stayed her she would join them. Alicia turned away from their vacant eyes and stiffened her back, locking her shock behind her occlumency shields.
For now, Alicia would go on.
Written for October Event: Bingo – Sectumsempra
Written for Ultimate Chocolate Frog Club: Alicia Spinnet