The Isis Collar (Blood Singer 4) Celia Graves was once an ordinary huone Now she strives toboth vampire abilities and the powers of a Siren Warned of a ical "bomb" at a local elementary school, Celia forces an evacuation Oddly, the explosion see both Celia and the FBI Teeks later, a strangely persistent bruise on Celia’s leg turns out to be the first sign of athe source of the plague isn’t Celia’s only concern Her alcoholic mother has broken out of prison on the Sirens’ island; her little sister’s ghost has possessed a young girl; and one of Celia’s boyfriends, a powerful e, has disappeared