Anybody figured out what to do about those stones that activate your medallion. Also anybody got the key to the chest there?
The key can be found after you activate Baltimore's Dream quest by watching the dream in the harpy queen's lair. It's possible that this can only be activated when choosing Iorveth's side, as those dreams are related to a quest only available there (saving Saskia). The key can be found in the old workshop of Baltimore, behind a breakable wall, where you also find a map in the form of a poem that points you to the chest and his secret rune cache. That chest you found has the key to the actual cache.