Possible Clues:

• Is able to take a journey for a spell
• Is liable to stumble as the result of trick
• Magical spell
• Unable to rest in peace for a spell
• Spell has power to wrong-foot
• The witch's spell makes it impossible to rest in peace
• The sort of spell a witch might be able to stumble on
• May stumble on account of old trick
• Magic spell needs special language to remove roughly
• Wilful piece of trickery or mischief