Rick Riordan. The Heroes Of Olympus. The House Of Hades (№ 280163)

My friend is dying. You can cure it or not?
Her voice wavered on the word "friend." Percy was to her much more. Even the word "boyfriend" does not cover everything. They've been through so much together that by this time Percy had become part of her - sometimes a very annoying part, but definitely that she could not live.