"The road is covered by jagged serrations of ice hard as iron. I pull aside the boot soles that are strapped to my feet. Underneath, my feet are streaked with cuts and dark abrasions. Thorns, branches and sharp ice graved their signs on me unknown, leaving behind a medley of runes written in some strange tongue." -- from the novel Sinful Folk http://sinfulfolk.com
Window frost (aka Jack Frost) forms when a pane of glass is exposed to below-freezing temperatures on the outside and moist air on the inside. Water vapor from the air condenses as frost on the inside surface of the window.