Grissom, Catherine and Nick investigate the death of a runner during a competition. Meanwhile Sara and Warrick investigate the death of a couple in a hotel room, initially thought to be a murder-suicide. Both cases take place during this 'cop' competition, with more than 20.000 attendants (all of them cops). This gives the investigations an interesting turn, as almost all the suspects and all dead people are cops.

Two young men are found murdered after scamming Sam Braun's casinos. Because of her relationship with Braun, Grissom refuses to allow Catherine to participate in the case, leaving the rest of the team to solve the mystery. One of the suspects is the son of a man who was black-listed for cheating years ago in Sam Braun's casinos. Sara finds out that Grissom recommended Nick for the promotion that she wanted.