The evil Dr. Shark is holding a cocktail party on his private island. Spies will try to gather clues hidden in the pool in order to build a case against Dr. Shark.
In turn, the players move their spy towards a free space at the bottom of the pool. They then gather clues by searching bare-handed in a bag, by following various directives. They could end up searching by only paying attention to the shapes or textures of the clues, search by the handful, or actually look into the bag to get the clue of their choice. The search ends if they find a shark or if the timer runs out.
They must then sort out the clues to work out the proof (the clues earned must correspond to the images shown on the tokens placed next to the game board). The game lasts a variable number of turns depending on the number of players. The spy with the most points when the game ends wins.