Just recently, I had a discussion with a friend about this card. It is true, that you play this event from shadows AFTER your opponent has declared all of his/her attackers right? I mean you essentially pay 5 gold for this event, so it has to be pretty good to be worth that cost. — The King in the North 1 7/31/19

That is correct. It's a reaction to the challenge declaration, so it happens after all framework steps of declaring the challenge (assigning attackers, stealth, etc.) — scantrell24 3392 7/31/19