Unorna could produce death in a form which could leave no trace, and it would be attributed to a weakness of the heart.

Does any one account otherwise for those sudden deaths which are no longer unfrequent in the world?
A man, a woman, is to all appearances in perfect health.

He or she was last seen by a friend, who describes the conversation accurately, and expresses astonishment at the catastrophe which followed so closely upon the visit.

He, or she, is found alone by a servant, or a third person, in a profound lethargy from which neither restoratives nor violent shocks upon the nerves can produce any awakening.

In one hour, or a few hours, it is over.