A disguised Hacker offers Jackie, Inez, and Matt an opportunity to play a game involving a hat containing the numbers 1 - 4. After picking two numbers from the hat, the player must multiply the two numbers, and if the product is an even number, the player loses. Matt runs in and plays the game but loses. Jackie and Inez assess the fairness of the game and find out the chances of winning are only 1 in 6. The girls develop a plan that helps them beat Hacker at his own game.

While hunting for a criminal who is good at hiding his face, Don asks Charlie to see which crime syndicates their suspect may be a part of. To figure it out, Charlie explains the belief propogation which takes scattered data and pulls it into a coherent image.

While Matt, Inez, and Jackie are searching for Digit, they come across a shop owner and play a game involving worms and hats. Each player chooses a color worm, and one of the players, Jackie, picks a worm from a bag to determine the winner. Lucky, who also works at the shop, ends up winning, and the trio believes the game is not fair. The shop owner explains that it is indeed fair because of probabilities.

Charlie discusses how he inputs numerous variables to construct a database of fire "fingerprints" to trace the arson back to the perpetrator.

In this clip, Charlie discusses the various data points he will be using to determine the identity of an arsonist.