This insidious loop relies on managing your life total down to 5 or less so that Second Chance's upkeep trigger can successfully resolve, sacrificing the enchantment to grant you an extra turn. Once Second Chance is safely in your graveyard, you activate Skull of Orm by paying five mana and tapping it to retrieve the enchantment back to your hand. You then simply recast Second Chance and repeat the process on each successive extra turn, chaining infinite turns together as long as you can fund the skull's activation cost and keep your life total appropriately low.