One day, a mysterious package arrives for the 'Running Man' members -- a photobook from an anonymous fangirl!�

Containing dozens of photos of 'Running Man' shooting locations and other landmarks, the cast embarks on a mission to decipher the secret behind the mysterious book.

What does it all mean, and who could be the anonymous fangirl? Find out on next week's episode of 'Running Man'!

Check out the preview below!

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