These stones are the work of corrupted Stonetalkers, the cruel spirits within respond to no one else. An Iron Heart is a knot of sacred iron ore, silverish and dull, the size of a clenched fist. At the touch of an evil Stonetalker a faint regular beat can be felt within. Bonding with an Iron Heart causes the Stonetalker 3 corruption.
By grasping the Heart and directing its will at a living creature the Stonetalker can cause the Heart to feed on the life of the target, drawing it into the Heart. Using the Heart in this way inflicts 1d8 damage to the target, ignoring normal armour. The victim's life is sucked into the stone, causing it to beat faster and grow hot, inflicting 1 Lethal on the Stonetalker. If the attack is continued then the stone grows hotter each round, inflicting 2 Lethal the second round and so forth. The Stonetalker gains 1 corruption each time they launch an attack in this way.
Once charged with energy the Stonetalker may draw power from the stone to resist damage or assault. Each attack stores one energy in the Heart, and each energy can be drawn off to prevent one damage from an attack, or to add 2 to a roll to resist a spell or attack. Stored energy bleeds away at a rate of one a day.
Only a Stonetalker can identify such a stone. They must be in an Iron mine, spend at least two weeks searching, and succeed in an identification roll resisted by a 25 (see Stonetalker rules).