The Doorman is the person that holds the key to Solla Sollew but has trouble trying to open the door due to a little troublesome creature called the Key Slapping Slippard living in the door-lock who pushes the key out the key-hole every time. He gives up trying to put the key in the the place of Solla Sollew so he tells the traveler that he is leaving going on the banks of River Wha-Hoo going to a new place called Boola Boo Ball on the river banks of River Who-Wall. He wanted the traveler to come along with him but the traveler "who been through so much trying to get to Solla Sollew" had other plans. He is a character from the book I Had Trouble in Getting to Solla Sollew.
