Silth said she was lacking in beauty and treasure, so she sent her children to Mossflower to plunder, destroy and steal from the locals. Everyone was afraid of seeing the Marlfoxes in the woods and made to tell the Redwallers. Silth was not at all well, her health was detoriating because she said she was being plagued by a "White ghost" which haunted her each night and said it was of a badger lord. Silth got scared every time she saw the "ghost" and killed any water rats who dismissed the ghost as false. She hated being disturbed and for her benefit Castle Marl had no steps, only ramps.
Silth didn't know that the "ghost" plagueing her was in fact a bedsheet set up by Lantur to deliberately kill her and blame it on the illness. The Queen's health and sanity got worse each night and eventually Silth died.