This was the work of the Goblin King, he was sure of it. The man excelled at trickery and deceit, with those treacherous crystals of his, and Didymus felt certain this place and this note were nothing more than a cunning illusion. He simply needed to find the edge of the orb -- no doubt this white line of which the missive spoke, and break through, in order to get back to Lady Sarah.
At least Ambrosius was there. Didymus never liked charging into battle without his loyal steed (whenever he could actually get Ambrosius to charge toward the battle, that was). After scooping the key of the table next to the bed (he left the flashing black box where it was, since it was nothing he easily recognized), Didymus climbed off of the bed and whistled to Ambrosius.
"Come here, boy," he called, as his mount made his way cautiously over. "Steady..." Didymus took hold of the saddle, heaving himself up, and then made for the nearest door. He had to stand in the stirrups to work the handle, but soon enough, he had the door open, and dug his heels into Ambrosius's sides. "Forward!" he called, and they trotted out into the hall.