Underground Toys The Mortal Instruments City of Bones Ceramic Heat Reveal Runes Mug Are you a Mortal Instrument... fan? When hot liquid is poured into The Mortal Instruments City of Bones Heat Reveal Rune Mug, a series of runes, previously shaded from human eyes, magically appears! This mysterious black ceramic mug is an ideal gift for any Shadowhunter in the neighborhood It holds 12 ounces