Demonspine

After solving her own murder and saving Heaven from a bureaucratic coup, Aggie retired from her three-day stint as a guardian angel. She has a contract with God to prove it-no one in Heaven will bother her until she dies again.
Except she didn't make that deal with the Devil. His favorite artifact has been stolen and for some reason, he wants Aggie to serve as his personal sleuth.
But really, what was Lucifer thinking? Aggie's completely mortal. Suppose for a moment she could actually procure a lead, track the thief back to Earth, and find their super-secret lair. Then what-knock on the door and ask for it back? And how is she supposed to defend herself when she inevitably gets busted snooping? Worst. Mission. Ever. Oh, and Lucifer conveniently forgot to mention that he won't protect her from all the enemies she makes doing his dirty work. Great.
Apparently, there's no such thing as retirement for guardian angels-even the clueless, wingless variety.