void main()
{
object oPC = GetEnteringObject();

if(GetIsPC(oPC) == TRUE)
{
object oTarget = GetObjectByTag("fr_iwd_fog");
int nType = DURATION_TYPE_PERMANENT;
effect eFX = EffectVisualEffect(APPEARANCE_TYPE_ZOMBIE_TYRANT_FOG, FALSE);

ApplyEffectToObject(nType, eFX, oTarget);
}
}