At Café Diem, Lexi is trying Vincent to be more thorough with his recycling habits. Zoe tells Carter of a three day yoga workshop, but he would not let her go, because she would miss school.
Thorne and Zane open the Cryptex security box, an alarm sounds and a cave is revealed, that houses an elevator shaft.
Meanwhile, at Tesla Shool, another secret entrance is revealed, and Zoe and her schoolmates explore, what lies behind it.
Lexi calls Carter and Henry for help, as he is trapped in a force field with her car. A mysteriously dressed "superhero" flies along and wants to help, but initially makes things worse. With the help of Henry, the situation is resolved, and the masked man flies away, after having some trouble with his rocket motors.
Lexi is at a hospital, and Chuck, the recycling chief, brings her flowers. Carter tries to find out the masked man's identity by talking to a scientist in the human flight department. He finds out that the rocket boots were developed there.
While running away from rats, Zoe slips and falls into a puddle of fluid, that shimmers briefly.
Fargo gives Carter a new piece of technology to replace his old radio, a transmitter, directly linked to his synapses. He is picked to test the equipment.
Carter and Lexi drive by a propellant pumping station that leaks gas. A spark from his malfunctioning transmitter sets off an explosion. The superhero appears, blows out the fire, thereby setting Carter's car on fire, walks through a fence, and flies away again. Investigations reveal that the gas leak was produced deliberately.
Zane finds the lost school kids and takes them to an underground lab, where they accidentally activate the security system locking them in.
Carter wants to set up a trap to catch the superhero by using Lexi as a bait. It works, but the masked man activated a device attached to his chest and runs away through walls, leaving back a finger. Henry suspects an old quantum phasing device be the cause of it, and Allison points Carter to a shut down project. He figures that the discarded material went to Chuck.
Zane manages to get a signal out, containing only numbers: 12393 3955 4891. Henry receives the signal and decodes the first two numbers as the coordinates Thorne gave him.
Carter and Jo visit Chuck's to find a prototype graveyard at his home. They also find the costume of the superhero and Chuck stuck inside a wall. He is released and brought into a lab to keep him in phase. Allison explains that the project was discarded, because people using the phasing device started to phase uncontrolled and eventually fell apart.
Carter figures out the meaning of the third number: it is Zoe's birthday. He asks Thorne about the location, she reveals it to be a pre-war complex underneath Eureka. Carter volunteers to use Chuck's equipment to walk through the walls and reactivate power to the complex in order to free the trapped persons. After walking through four doors, he is still out of phase after deactivating the device. He uses the spark from his malfunctioning comm device to set off the generator and restore power.
Henry and Allison find a way to reverse the effects of the phasing device to save Carter and Chuck.
Carter confronts Thorne about what she is looking for, but she refuses to tell him. Later, she picks up a kind of key from her safe and enters the complex with it.