Possible Clues:

• Undependable
• Er lumber room sounds not a regular place
• Irregular in pattern
• Fickle chap caring for rodent
• Not at all consistent
• Sort of criteria I once dismissed as unpredictable
• Wayward boy about to betray one's trust
• Unstable
• Not even little by little, a traitor infiltrated
• Racier novel set around time that is unpredictable