While visiting an old girlfriend who's a park ranger at a wildlife reserve, MacGyver runs into deadly poachers who are intent on hunting animals on the reserve. When MacGyver tries to uncover their plot, they come after him. Now it's a race against time to escape the poachers, save the animals, and save their own lives.
After MacGyver witnesses someone dumping toxic waste that's polluting mountain streams, he and Pete enlist a reclusive mountain man nicknamed "Earthquake" to help lead them to the culprit. Things become complicated, though, as Earthquake's flashbacks to his military service in the Vietnam War make him unstable and threaten their case.
After returning home from a long assignment, MacGyver has an unwelcome surprise. Jack Dalton is waiting and wants him to help with a new scheme. A wealthy woman has just acquired some invaluable jewels, needing Jack to fly her back to her home in France. Things seem to be going fine, that is, until they land. Jack and MacGyver are arrested and accused of theft.
While back in Minnesota to fill in as coach for a high-school hockey team, MacGyver tries to change the attitude of a callous player who has a shot at playing for the pros. But when this kid's ambition lands another player in the hospital, MacGyver must try and find out what or who is pushing him so hard to succeed.
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.
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.