Percy and The Dark Mistress played the diversion perfectly as they made it into the Department of Mysteries without any trouble. Ogden had incapacitated the last Unspeakable, Croaker, weeks ago. The Dark Lord had been told by his Unspeakable Death Eater, Rookwood, about the Fate Chamber. It was locked at all times in order to protect the Fates from doing exactly what they were about to do.