MacGyver teams up with colleague Nikki Carpenter to find out who is behind the attempts on her life. When they find out that the man who tried to kill her is connected to two terrorists who blew up a local post office, MacGyver and Nikki must find out what the terrorist's next target is before it's too late.

While testing a new nuclear bomb defusing team at the Phoenix Foundation, a deadly explosion kills three men. Pete blames himself for not inspecting their equipment better and resigns from his job out of guilt. However, Pete is replaced by a not-so-trustworthy man—one who may have been connected to the explosion.