Disclaimer: I don't own Harry Potter. I'm just having a bit of fun with the universe and characters.
A/N: This was written in response to the prompt:
Harry Potter, Luna Lovegood, weapon
Defense, Offense, and Mice
At the same time that rumors had started about a new generation of Death Eaters planning an attack on the 10th Anniversary of Voldemort's death, Luna Lovegood started carrying around two white mice in her pockets.
"It's only prudent," Luna explained in her soft voice. "You never know when you might need a mouse. And it's better to have two so that you can share. Would you like one, Harry?"
"Uh, no, thank you, Luna."
He had other things to worry about, what with security for him and his family at the celebratory feast the Ministry of Magic was hosting in his honor. It was a good thing he had worried, because when the neo-Death Eaters attacked, Harry had a portkey handy to send the children home. He and Ginny stayed and fought.
He couldn't leave with the children, and even as the green light of a death curse came at him, he knew he couldn't have made any other decision than to come to the celebration and fight his hardest.
Apparently it wasn't his time to die yet, though, because a gently tossed white mouse intercepted the deadly green spell.
The spell fulfilled it's purpose and the mouse died.
"Mice are so very useful," Luna smiled faintly.