In Peril in Pelargir nightmare mode, Cunning Informant effectively lowers the engagement cost of all enemies. Let's say there is a Pelargir Ringleader in the staging area in the encounter phase, along with another enemy with higher engagement cost. After I make the first check (against enemy X), I engage the Ringleader, who brings in a Cunning Informant. I've already made my engagement check against the enemy sitting in the staging area, so would I make another and engage me due to the Informant's effect? I'm guessing not, but I want to be sure.
For reference:
http://hallofbeorn.com/LotR/Details/Pelargir-Ringleader-PiPN
http://hallofbeorn.com/LotR/Details/Cunning-Informant-PiPN
Thanks.