This might explain the cover:
One day Kil Bruner was a solid Class A engineer in a society of World Police and citizen Files, jet-set migrants and status-ranking Stability keys. But the Police ordered Kil to forget about his missing wife Ellen - and that was a mistake.
Because Kil would move Heaven and Earth to find the woman he loved. Literally.
Status-ranking stability keys, you say. The ebook has the keys on the cover. They must figure somehow, but I doubt huge keys are flying around the city. That would be stupid DC stuff, where Superman was opening six-story locks with a huge key that was blasted into space when Krypton exploded and just managed to land in the arctic.