Amari and the night brothers / B. B. Alston.

Amari Peters has never stopped believing her missing older brother, Quinton, is alive. Not even when the police told her otherwise, or when she got in trouble for standing up to bullies who said he was gone for good. So when she discovers a ticking briefcase in his closet containing a nomination for a summer tryout at the Bureau of Supernatural Affairs, she's certain the secretive organisation holds the key to locating Quinton -- if only she can wrap her head around the idea of magicians, fairies, aliens, and other supernatural creatures all being real. Now she must compete for a spot against kids who've known about magic their whole lives. No matter how hard she tries, Amari can't seem to escape their intense scrutiny and doubt -- especially once her own supernaturally enhanced talent is deemed 'illegal'. With an evil magician threatening the supernatural world, and her own classmates thinking she's an enemy, Amari has never felt more alone. But if she doesn't stick it out and pass the tryouts, she may never find out what happened to Quinton ...

9-12 years.