TV HIGHLIGHTS

MacGyver, 8 PM on Ch. 7 and Ch. 12: Mac and

Riley (Lucas Till, Tristin Mays) travel overseas together on a mission to prevent the collapse of a fragile government in the new episode “C8H7ClO & Nano-Trackers & Resistance & Maldives & Mind Games.” During their operation, however, the pair inadvertently inhale some deadly microscopic technology. Meredith Eaton and Henry Ian Cusick also star; the guest cast features Deepti Gupta, Scott Holroyd and Alexandra Grey.

Magnum P.I., 9 PM on Ch. 7 and Ch. 12: A married woman turns to Magnum and Higgins (Jay Hernandez, Perdita Weeks) to track down her lover’s killer because she doesn’t want anyone to expose her affair to the police in the new episode “The Lies We Tell.” Soon, however, they discover the dead man wasn’t who he claimed to be. Meanwhile, Rick (Zachary Knighton) visits Icepick (recurring guest star Corbin Bernsen), whose health has taken a turn for the worse. The guest cast also includes Christopher Thornton, Betsy Phillips and Elyse Levesque.

The UnXplained, 9 PM on HIST; 12:03 AM on HIST: Serial killers are terrifying on several levels, but on reflection, it may be the total disregard — even contempt — for human life that shocks our instinctive sense of humanity and makes “normal” people fear for their safety and security. An episode called “Serial Killers” examines how these murderers almost never show any empathy for their victims or remorse for their crimes, raising questions about the cause of such a chilling defect in the human psyche. William Shatner is the host.