Eventually, Fingon might look back on that conversation and wonder about some of the details. What is dead cousin Finrod's favorite necklace doing outside of insular, paranoid Nargothrond, for example. Who exactly Dior is.

Absolutely none of that is relevant, because Fingon is putting the relevant pieces together and they are hideous.

"So you invaded." The horror and fury color his voice the longer he sits with the knowledge. "A second kinslaying, Russandol? Have you completely lost your mind?"