Possible Clues:

• Difficult to understand, obscure
• It's hard to understand a goody getting right into evil behaviour
• Hard to understand, recondite
• It's not clear why one could be swearing around half the street
• Obscure surgeon breaking a verbal suspension of hostilities
• Hard to understand, complicated
• Strange busts are difficult to understand
• Clear as mud
• Silly stab at trick that's hard to understand
• Difficult to comprehend