Horatio and Speedle's case hinges on the testimony of a forensic-evidence enthusiast who stole a blood-drenched latex glove from the scene of the murder of a man who was stabbed to death with a butterfly knife. When Speedle tracks him down, the CSI wannabe is impressed by the ease with which Speedle was able to locate him, and the two begin to develop a slight bond when he shows up at the crime lab the night before he is set to testify. However, their relationship is cut short when the young man is found dead in his forensics-shrine of a home. Meanwhile, Delko and Calleigh probe the shooting death of a young woman whose body is found wrapped in a plastic garbage bag in a dumpster near the ritzy Miami club where she worked.

E-mails and text messages trigger a mass gathering of students to perform a random task on a golf course. However, as the crowd disperses, the body of a high school student is found. The original message triggering the "flash mob" is traced to a high school senior whose father is a high-powered defense attorney. The case changes direction when Horatio and the team learn that the schoolmaster's daughter may have had something to do with the murder and evidence reveals that the victim was having an affair with his chemistry teacher.

A murder investigation takes Horatio and the team into the world of speed dating. Richard Laken is found killed by a tire iron outside a lounge following an evening of speed-dating. The team discovers his car is covered with acetone, which traces back to one of the female guests. She reveals that she dated Laken and he dumped her, so she doused his car with nail polish remover for revenge, but she didn't kill him. Now, when Horatio and the team learn that Laken recently witnessed a serious assault at a Miami Heat basketball game, they are on the hunt for two perps instead of one.