When the fifteen-year-old Brian Haddick is found beaten to death with a hammer in a construction site, Grissom, Sara, Warrick and Capt. Brass investigate the case. They request the hammers of the workers and they find blood in the hammer of Gregory Curtwell, but he says that he was travelling. They learn that his sister Ashley is involved in the case and claims that Brian was raping her. Meanwhile, Catherine, Nick and Det. Sam Vega investigate the murder of Marlene Mitchell, who was shot while separating a fight between her husband Stewart Mitchell and her ex, Todd, in front of her new house. They need to use their knowledge of trigonometry and physics to resolve the case.
—Claudio Carvalho, Rio de Janeiro, Brazil