If this card was Set by the effect of an "Altergeist" card, you can activate it the turn it was Set.
When this card is activated: Send 1 "Altergeist" monster from your hand to the GY.
When your opponent activates a Trap Card (except during the Damage Step): You can send 1 "Altergeist" monster from your hand to the GY; negate that effect, and if you do, destroy that card.
You can only use each effect of "Altergeist Haunted Rock" once per turn.