Magnum P.I.

9 p.m. on CBS, CBS-R

Magnum and Higgins (Jay Hernandez, Perdita Weeks) are understandably shaken when one of her former MI6 colleagues abruptly turns up nursing a fresh gunshot wound in the new episode “Day of the Viper.” They’re even more alarmed, however, by the news he has to deliver: The assassin who killed Higgins’ true love has resurfaced on Oahu. While he and Higgins spring into action, Magnum asks Rick (Zachary Knighton) to take over a case, which unfortunately soon goes sideways. Ian Pryce guest stars.

Perdita Weeks and Jay Hernandez star in “Magnum, P.I.” on CBS.