Christopher Stapleton

A computer expert (Danica McKellar) claims to have witnessed a murder in the apartment across the way, but investigators find no physical evidence of a crime.

House and the team treat a high-profile fitness trainer who collapses while shooting an infomercial; Thirteen participates in a clinical trial led by Foreman.

Horatio and Delko head to Brazil to try and catch Marisol's killer, Antonio Riaz. While in Rio, Horatio reunites with Yelina and learns that his brother Raymond is in too deep undercover in a drug ring run by Riaz. To make matters worse, Horatio's nephew, Ray Jr., is working as a drug mule for Riaz. With the stakes set high, Horatio must catch Riaz before he takes the life of another member of Horatio's family. Meanwhile, in Miami, Natalia butts heads with Ryan as she struggles through her first case as a field agent..

The CSI team delves into the world of political corruption when a corporate fixer is murdered.