SPOILER WARNING: This article contains major spoilers for "Blurred Lines," the latest episode of Supergirl.
Welcome to the Arrowverse, Sean Astin!
In "Blurred Lines," the latest episode of Supergirl, the Stranger Things alum appeared in a guest role. The episode saw Malefic J'onzz, J'onn's forgotten brother, transform into Kelly Olsen's friend Pete Andrews. Astin played Andrews, as impersonated by Malefic.
Last week, Malefic realized Kelly had the key to unlocking his psychic abilities, which allow him to control other people's bodies. Kelly works as a psychologist for Obsidian North, a tech company using virtual reality and Q-waves to help those affected by PTSD and paranoia. Knowing these Q-waves could restore his powers, Malefic masqueraded as Andrews to convince Kelly to help him, allowing him to infiltrate Obsidian North with minimum conflict.
First, Malefic broke into Alex and Kelly's apartment. He observed several photos of Kelly, some of which saw her in army fatigues with Andrews and other friends. He borrowed Andrews' likeness and headed to Obsidian North, where Kelly instantly recognized him. He told her he was in town and had stopped by to see her. When she said they could catch up later, after work, he pushed her. "I think I need help," he said. Kelly was unable to ignore his plea and told him to come by later so they could figure something out.
When he returned, Malefic convinced Kelly to try this new Q-wave therapy on him by telling her he would hurt himself otherwise. She hooked him up to the machine, which began to map his mind. Soon, the truth became evident to Kelly, but it was too late. The Q-waves had done their work; Malefic could now control other people's bodies at will.
Malefic immediately used this on Kelly to prevent her from calling for help. He also attempted to make her kill herself, but J'onn intervened. The two bothers hashed it out, yelling at each other in Martian. J'onn revealed he was to blame for erasing Malefic from the Martian hivemind and banishing him to the Phantom Zone. They fought and Malefic was able to escape, but not before Kelly revealed she could now recognize Malefic no matter what form he took.
This ability makes Kelly a major threat to Malefic. As such, she has now become one of his primary targets. To protect her, the DEO sent her and her brother James into hiding for the time being. At the time of writing, it is unclear how long Kelly and James will be absent from the show.
Airing Sundays at 9 p.m. ET/PT on The CW, Supergirl stars Melissa Benoist as Kara Danvers, David Harewood as Martian Manhunter, Mehcad Brooks as Jimmy Olsen and Chyler Leigh as Alex Danvers.