Dear Insanity

She's known as the Mute Murderer, the girl who's parents commited double suicide on her 16th birthday. Ever since, she's been silent.
For two years she's been in the most well known mental institution in England, wasting away (silently, of course) with hallucinations of murder and suicide. The day she turns eighteen, though, she's let free onto the streets of ever-prosperous England. Armed with coffee and cigarettes, she wanders the streets.
It's there she meets Gabriel, who refuses to leave her side. He doesn't know her past, or her real name. He knows nothing but the words engraved on her dogtags:
Alexxa.