Dexter s world of police analyst by day, and serial killer by night, is rocked when he s privately contacted by another serial killer, whom the department is investigating, who claims that the killer knows about Dexter s double life. Meanwhile, Dexter s sister, Debra begins investigating the mysterious killings with Dexter s help, but who lets her take the credit. She then finds a stolen refrigerated truck which contains a gruesome message. Dexter also begins stalking his next victim, a wealthy businessman who gets acquitted of a drunk driving charge. Elsewhere, Sgt.