An old friend's heart problems reveal a bigger issue; Devon treats a woman who might be a good candidate for deep brain stimulation.
After escaping Purgatory, a warlock who triggered the Salem witch trials returns to find a dangerous book of spells. Meanwhile, Abbie attempts to trust Frank Irving again, while Henry struggles to find his identity.
Stacy is concerned about her unborn baby; Grayson and Jane work together on a case involving national security.
MacGyver 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
Nick tries to defuse a possible turf war between werewolves and vampires; Brett and Andie's relationship rekindles; Mia turns to Devon for guidance.