[His lips press together as he gathers his thoughts and when he talks his hands go along and speak at the same time.]

Trying to communicate or look into what the castle is directly, there's something and nothing there. Like a void that is filled, I found, which is an interesting paradox. I likened it to trying to catch smoke with a net, and the castle didn't like that I tried. Overall it wasn't a pleasant experience, but the effects were not long lasting. To paraphrase your own words, if you push, it pushes back.