The partying son of a Serbian war criminal takes his new bride to an exclusive French chateau for their honeymoon, and Matty assigns Leanna to work with Bozer, Mac, and Riley to go undercover and find out where the father is. Meanwhile, Jack convinces Elwood and Jill to help him break into Matty's house to find out what she's hiding from Mac.
Three months after quitting the Phoenix Foundation and moving to Nigeria, Mac puts aside his differences with his father and returns when he hears that Jack is the target of a murderous dictator he double-crossed.
Jack receives an emergency distress signal from one of his old Delta buddies who has been accused of terrorism in a foreign country; he and Mac quickly recruit the rest of Jack's old Delta team and stage an unsanctioned rescue operation.
Mac and Riley must find a way to drive a tanker filled with liquid oxygen through a region occupied by rebels and deliver it to a children's hospital; Riley helps Mac decide whether or not to allow his father back into his life.
When Oversight's attempt to capture a cartel's leader goes bad, MacGyver and Jack rush to Mexico to pull their boss out while racing through the heart of the country during Dia de Muertos celebrations. Also, Bozer and Riley use Halloween as a distraction to gather intel on a man accused of treason.
Matty sends MacGyver and team to Ghana to recover a hard drive from an e-waste landfill that is run by a powerful and violent man. But when Matty refuses to reveal what's on the drive, other than a mysterious file called 'Dragonfly,' the team speculates about what could be so important to her.