Mysterious disappearances are occurring all over the planet Mobius, and Sonic sets out to solve the mystery. He tries to create a profile of the criminal based on eyewitness accounts, but it doesn't work out so well.
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.
In this scene, Charlie explains how the drops of water coming from a sprinkler can be used to extrapolate the sprinkler's location. He then explains how, by modeling what the previous crime scenes have in common, they can determine the killer's home.