I must "use" a book from your inventory to activate this door to the Hall of Echoes (if I remember good).
Beware!! SAVE before going in AND make an extra savegame from the moment BEFORE you go IN the Hall of Echoes
On 7th of february 2015 : I start a new adventure in the Divinity world of Original Sin, it's a Fantastic Freaking Fabulous Funny ... it's my All Time Favorite One !
