An old friend asks Cal to look into the theft of the formula for a new drug after a knockoff surfaces and causes three deaths. Meanwhile, Gillian and Eli help the U.S. government negotiate the release of two Americans facing execution in Yemen for possession of marijuana.
Gideon, Hotchner and their team reopen the unsolved case of a serial killer who has attacked someone for the first time in 20 years.
Clark and Sipowicz interrogate a pedophile in the case of a missing child; while investigating a murder, Ortiz and McDowell question the grandson of the dead woman.