Wow, I once thought there'd be another citadel in the arctic. And by the way, have you ever played Penumbra: Overture? It takes place in Northern Greenland, in an abandoned mine with a research base built below it, and nearby is a frozen lake that two people were exploring. It made me ponder if Gordon was one of them because there's a hand clutching a crowbar there. (It's not Gordon, because a note there says it's "Joe Freeman") but the possibility makes me wonder all the same.