Half Brother

Ben struggles to adjust to Zan’s absence. Everyone at school is sympathetic, and Ben resolves to get Zan back. He calls Peter regularly to check in on Zan. Richard and Sarah send Ben to therapy, where he expresses anger toward Richard.

Ben attends the last school dance and kisses Shannon. As the school year ends, Ben and Sarah plan a trip to see Zan. Despite his terrible year-end grades, Richard is more understanding than usual.

Sarah and Ben drive to Nevada, enjoying each other's company. Zan recognizes Ben, but Ben notices that Zan has a missing tooth, which was knocked out by Zeus against the cage bars.

Peter explains that Zan is having trouble adjusting because he does not know how to communicate as a chimp. Peter invites Sarah and Ben over for dinner and shares his concerns about Helson. Peter stole one of Helson's letters from the Thurston Foundation, a biomedical research lab known for its cruel treatment of animals. They illegally open the letter, which offers Helson $30,000 for three of the younger chimps, including Zan.

They decide to steal Zan.