Zoe is a character exclusive to The Handmaid's Tale television adaption. She is the leader of a small group of refugees attempting to flee the Republic of Gilead, who takes in Luke. She appears in the episode The Other Side and is portrayed by Rosa Gilmore.
Nothing is really known about Zoe's background, though she is described as being an "army brat," and was very likely serving in the military, being "stationed in South Carolina" around the time of the Gilead-takeover. She was proficient with firearms (Zoe was seen armed with a Colt M1911A1 pistol when she picked up Luke) and also has medical training.
During the period after the Sons of Jacob's coup d'état against the United States government, Zoe and a couple of US Army soldiers she was stationed with in South Carolina were among the first people to discover the Republic of Gilead's Handmaid program when they found a high school gym filled with young women held under armed guard by the Guardians. Many of the women in the high school gym had their children taken away by the Guardians and the women were in process of being turned into Gilead's first batch of Handmaids.
When the Republic of Gilead came to power, Zoe prepared to flee to Canada and picked up several other escapees along the way, unable to bring herself to abandon them, including a Catholic nun named Christine; a gay man named Peter, a driver named Lila, and an unnamed woman (later revealed to be named Erin) whom she liberated from a Red Center.
The Other Side
Zoe is looking for supplies in an abandoned town near the Canadian border when she and Erin come across the injured Luke, who had escaped from the Guardians after the ambulance they were transporting him in crashed. Due to the fact he is wearing a Guardian coat and was carrying a Glock 17 handgun he took from a dying Guardian, Zoe and Erin believe him to be a Guardian, with Zoe holding him at gunpoint until he convinces her he is not. Zoe inspects his bullet wound and determines he will die from bloodloss unless she helps him. She and Peter carry him to the bus they are using as transport and she treats his wound, saving him.
When a slightly recovered Luke tries to get off the bus, demanding that Lila pull over, Zoe puts her hand on her gun, subtly threatening him into sitting down, as it is too dangerous to stop. When they reach the border, Zoe offers to let Luke come with them, saying they have bartered passage to Canada on a motorboat that is picking them up after dark. Luke refuses, insisting on heading back to Boston to try and find his wife June and daughter Hannah, who were taken by Gilead. Zoe takes Luke to a nearby church and shows him dozens of bodies of men and women strung up from the rafters by their necks, graffiti covering the church's interior walls calling the church's congregation "gender traitors" and all the church's stained-glass windows and statues smashed (all of this vandalism was done by the Guardians personally). She forces Luke to look at them, telling him that these people attempted to hide the fertile women from the regime inside the church and fought back. As a result, they were all executed by the Guardians. Zoe says that anyone who rebels or is deemed to be of no value to Gilead ends up this way and that if Luke stays, the same will happen to him, leaving his family alone. Zoe also tells Luke the US Government has people in Canada that can help him in rescuing his family from Gilead.
This finally convinces Luke to join them in escaping to Canada. When the boat driver insists Luke has to pay for his passage, Zoe becomes angry and tries to stand up for him, but the driver dismisses her. After Luke hands over medicine and his gold wedding ring, he is allowed onboard, only for Gileadean patrols to ambush them, opening fire on the boat and those attempting to board. Zoe engages them in a firefight in an attempt to hold them off, but is shot in the chest and fatally wounded.