Grease off the processing machinery. We cut into a fruitcake one time and it had a huge greasy metal machine nut in it. Baked up with the batter.
Good eye. Or the tell-tale sound of the knife hitting it. Not like it would have stood out from the normal ingredients.
Shi'Terra
This really is one of the more unfortunate names. Put it together with your fruitcake story and it hearkens back to Cousin Eddie, outside in his bathrobe with a Christmas greeting.
Merry Christmas, Shi'Terra ...