Standard disclaimer here.
The day she died, he made a vow.
He touched his trembling fingertips to her scarlet-stained temple, shedding silent tears on her motionless corpse.
Something in him snapped, something in him withered away, and a large part of the boy called Faust passed out of the world in which his body dwelled. The instant he resigned himself to the fact that she was beyond his medical expertise, he signed a pact with the devil, trading away his humanity for one last chance with his beloved Eliza.
He could see them; he had always been able to see the phantoms of white, and gray, and black that flitted behind his eyelids and in front of his face. Now their forms seemed so much clearer- so much more precise- now that he had no last traces of reason in his mind. They spoke to him sometimes, whispering sweet nothings in his ear, telling him tales of those that had died and remained in the world. Ghosts. He could see them, and he could hear them, and part of him almost thought that he could feel their cool fingertips across the back of his neck. His logical mind concluded that they must, therefore, be.
He sealed her up tight in an allegorical jar of formaldehyde, the pretty woman he was quite determined to preserve for all time
He would run callused, numb fingers over her skull late at night, whispering sweet nothings to her in the darkness.