The CSIs must find the killer after a young woman is pushed in front of a moving bus. Alexx finds a bruise shaped like a hand imprint on the victim's back, proving that she was pushed in front of the bus and her boyfriend, Jay Seaver is the prime suspect. When one of Jay's office rivals turns up dead, Jay reveals that he has a psychotic stalker, Claudia Sanders. Later, a man's body is discovered down an elevator shaft in a nearby building. Meanwhile, Calleigh's father seeks her help when he fears that he might have killed someone after a night of drinking and Horatio assigns a new CSI, Ryan Wolfe to the case much to Calleigh's dismay.
- Former beat cop/CSI Ryan Wolfe is introduced for the first time.
- Ryan eventually joins the team, becoming Tim Speedle's replacement.
- The song playing while Ryan is searching for evidence in Kenwall Duquesne's car is "On My Own" by Ulrich Schnauss.