The beginnings of a story idea…
Centuries ago a Dark Fae names Azrael committed an ultimate sin by having an affair with a Summer Fae named Holly. This went against the laws of both the Summer and Winter courts. When the truth was found out, both were banished to the world of the living.
Unknown to Azrael, Holly realized that they both made a mistake, and appealed to the Summer and Winter Queens to end their banishment. After a short deliberation, both Queens agreed to allow her to come back to the Summer Court, but in a stunning turn of events, the Winter Queen did not want Azrael to come back to the Winter Court.
For centuries, Azrael sought out his lost love, not knowing that she was back in the Summer Court. He became despondent, turning to various vices to fill the void, but to no avail. Then he tried finding love from ordinary humans, but none could survive the ordeal of being loved by a Fae. The humans that went missing over the years became a string of unsolved disappearances that have various police departments baffled.