Sleuth Ball by Iarvel Magic

Do you have the ability to discern whether your closest friend is being honest? Absolutely, if you've known them for years. But what if it's someone you've only met once? Can you tell every single lie from a stranger? Very unlikely.

Introducing Sleuth Ball, the remarkable prop that allows you to see through deception and pinpoint who has the black ball.

BASIC EFFECT:

Five balls, four white and one black, are distributed to five audience members to conceal in their pockets. The person holding the black ball must always lie when questioned by the mentalist, while the others tell the truth. No matter how cunning the black-ball holder is with their lies, the mentalist will unerringly identify them each time.