Possible Clues:

• Mask at one time put in cradle regularly
• Study exotic lace mask
• Hide in study -- set apart, by the sound of it
• Prevent from being discovered
• Hide in attic, once alone
• Person inside ruffled lace mask
• Hide as soon as in California
• Study what sounds like marine mammal's hide
• Keep out of sight one time during short visit
• Shroud