You inscribe an arcane glyph onto the ground using amber dust. Once the spell's casting time is over, the amber dust becomes invisible. The spell is triggered when any creature walks onto the invisible symbol. That creature has its memory of the last five minutes wiped and is returned to where it was and what it was doing five minutes ago with no memory of triggering the glyph. Therefore, it will trigger the glyph again, and again, and again, etc. The creature is trapped in a time loop. The spell prevents anyone interfering with what the creature is doing, as it cannot see, hear, smell, or feel anything trying to interfere with the loop. The only way to end the loop is to cast Dispel Magic as a 9th level spell on the glyph, therefore ending the spell as the creature who originally triggered the glyph can no longer trigger it. At the casting of the spell, the caster can specify up to 10 creatures, or 5 creatures and one type of creature, such as humanoids, that cannot trigger the trap.