I'm thinking about Gildor Inglorion boon from The Black Riders.

When destroyed is he removed from play, placed in the discard pile of the encounter deck, or placed in my player card discard pile, or something else?

I couldn't find this in the FAQ or with Google.

Thanks!

He's a boon rather than an objective ally, but it doesn't matter for your question. He goes to the discard pile; if something else is supposed to happen to the ally, it will be printed on the ally itself or on another card in play (like a quest card). An example in Celador from Into Ithilien, his text says: While Celador is in the staging area, he is committed to the current quest. Forced: After players quest unsuccessfully or a character leaves play, deal 1 damage to Celador. If Celador leaves play, remove him from the game.

So, if nothing is telling you otherwise, the ally goes to the discard pile. Gildor can be revealed again later in the scenario if you reshuffle (or if you tech for it, like bringing the player card Shadow of the Past).

To be clear: which discard pile? (Encounter or player? The card's back is an encounter card.)

(Also, he is a boon, but his card is also labeled "objective-ally".)

Encounter deck discard pile

And I stand corrected about the objective ally thing

Thanks. So I guess that does means I could have got him back again on a reshuffle, after all. (That didn't happen though, as I won on the next turn.)