Use once as a free action: every enemy piece currently attacking one of your pieces flashes on the board until your opponent replies.
You draft Threat Ledger in either mode. Free action: you choose when to use it, and it resolves without costing your turn.
As a item card, it is a one-use consumable, drafted in either mode.
“Double-entry bookkeeping: their attacks on the left, your worries on the right.”