Talla returns to the Orville on a shuttle. She checks in with Grayson and fills her in on her visit with her parents. She also reports detecting the residue of a Kaylon ship on her way back to the ship.

Talla shares chocolates from her home planet. Bortus informs her that he is dieting in preparation for shore leave.

Isaac informs Mercer that he has detected narrow band electromagnetic emissions from a previously-thought barren and uninhabited planet, Neron 1. Talla backs him up.

Mercer orders a course alteration to investigate. When they arrive, Isaac’s scans show the signs of multiple advanced cities and a population of 8.5 billion.

Talla hails them but there is no response.

Mercer assembles an away team.

As they approach what should be a major city, they see nothing but forests. They land and confirm what they’re seeing with scans. They contact LaMarr on the ship and he informs them the cities are gone. The planet is covered in dense vegetation instead.

On the planet, Bortus detects several hundred humanoid lifeforms. They arm themselves and make their way towards the settlement. When they emerge from the forest, they find a building with a sign reading, “Oakwood High School.”

Mercer contacts LaMarr again, but the ship’s scans only read the landing party. They aren’t picking up the lifeforms Bortus detected or the high school.

The landing party enters the school. It looks like an old Earth high school but Mercer is no longer able to contact the ship. They are unable to open the door or break the window.

The bell goes, the classroom doors open, and the halls fill with regular-looking students.

They split up to investigate.

Onboard the ship, LaMarr wants to send a second landing party to look for the first. When Isaac points out the danger in doing so, Burke shouts him down. LaMarr orders Isaac to lead the second landing party and to take Dr. Finn.

Talla and Bortus enter a History classroom. The teacher throws them out for disrupting the lesson and trying to break the window. When they’re back in the hallway, they realize Malloy isn’t with them anymore.

Three bullies grab Malloy and beat him up in the bathroom, demanding money from him.

Talla finds Malloy’s com scanner outside the bathroom but she and Bortus are unable to open the door.

The bullies continue to beat on Malloy, sticking his head in a toilet, until he agrees to pay them. They beat on him a little more then leave. Talla and Bortus get in the bathroom through the open door after the bullies exit.

They meet up with Mercer and Grayson and share the information that Malloy’s wounds are real.

In the lunchroom, they meet some mean girls and find seats with other students who warn them about Randall.

Isaac and Dr. Finn take their shuttle down to the planet with two other landing party members.

At three o’clock, the school dismisses and the first landing party follows the students outside. They still can’t contact the ship and the shuttle has disappeared. They decide to find Randall.

They head onto the sports field and the bullies meet them. Randall is a huge alien orc-like creature. He picks up Malloy. Malloy’s eyes go white. Talla grabs the back board off a bench and spears Randall through the eye. Randall drops Malloy and his eyes go back to normal.

Randall chases them back into the school, but when they enter the school, they find themselves on a passenger plane. They take their seats.

Malloy tells the team what it felt like when Randall was holding him.

Isaac and Dr. Finn’s shuttle approaches a barren, desert planet.

They contact LaMarr and report the planet is what they’d always known it to be. They can see the first shuttle. They enter it and it is empty.

The passenger flight goes through a storm. Malloy notices the pilots seem to be purposefully seeking out rough turbulence.

They head for the cockpit and Talla rips the door open. There are no pilots. The flight attendant insists they sit back down. Grayson punches her out.

Malloy takes over the controls. The fuel is almost gone and then the engines stall. Bortus spots a clear space in the mountains and Malloy attempts to glide the plane to a landing. As they’re crashing, Mercer’s eyes go white.

The plane comes to a stop, precariously balanced over a gulch. The team leaves the cockpit and finds the plane empty. They exit the plane and find themselves indoors. Bortus’s scanner detects a nearby open chamber.

Mercer has sustained a head injury. He tells Malloy that he had the same feeling of dissociation just before they crashed.

The open chamber is filled with floating metal egg-shaped pods. Bortus informs them it is a Moclan morgue.

As Talla passes a screen, it lights up and she presses a flashing shape which opens the pods. One of the dead appears to be Bortus. As Bortus leans in to look closer, the dead Moclan’s eyes open and it grabs Bortus. Bortus’s eyes go white but revert once he is freed of the dead Moclan’s grip.

He admits to feeling the sensation Malloy and Mercer experienced.

At the other end of the chamber a doorway appears. Looking through it, they find a long stairway leading down into darkness.

Isaac reports what the shuttle’s log has on the first landing party. LaMarr orders Isaac and Dr. Finn to return to the ship.

Mercer’s landing party walks down the stairway, exit through a portal at the bottom, and find themselves on the shore of a lake. Talla recognizes it as a lake on Xelaya.

Mercer deduces that it’s all an illusion since Xelayan gravity would’ve killed everyone except Talla instantly.

Malloy and Grayson notice a flashing pattern coming from the far side of the lake.

Talla spots a raft. Talla, Malloy, and Grayson take it across the lake. Something very large swims under their raft. Grayson is grabbed by a tentacle and dragged under. Talla dives in after her. As they struggle with the creature, Grayson’s eyes go white. Talla frees her and they swim for the surface.

They return to Mercer and Bortus since the flashing light has disappeared. Talla reports she experienced the disconnection and so does Grayson. The ground near them suddenly turns into steps leading to a doorway.

Mercer refuses to keep walking the path being laid out. He leads them in a different direction. Eventually, Bortus’s scanner picks up a power signature coming from a cave. They find a holographic projector unlike anything they’ve ever seen. Bortus deactivates the protective shield. Mercer destroys the projector and everything around them disappears and the desert planet returns and they’re standing right next to their shuttle.

Mercer contacts LaMarr and reports they’ll be returning to the ship right away. They gather up the pieces of the projector for analysis.

Back on the ship, Dr. Finn scans them all and finds the same signs of an invasive neurological effect.

Isaac and LaMarr’s analysis of the device shows that some elements are of Kaylon design. They believe the Kaylon’s are trying to control people’s mental perception.

Grayson and Mercer report to Halsey. He sends a ship to pick up the pieces of the device for further study.

As the Union convoy approaches, Isaac alerts them to the fact the ships are in fact Kaylon spheres. The scans show Union ships. Isaac insists they are being deceived.

Burke tries to argue that Isaac can’t be trusted. As the ships close in, Mercer orders red alert and for the Orville to move away. The ships reveal themselves to be Kaylon spheres. They pursue and fire. The quantum drive is fractured and they cannot engage it.

On a suddenly calm bridge, LaMarr is informed of an incoming transmission from Talla. She’s been waiting at the rendezvous point for three hours. LaMarr fills her in on what’s happened and tells her to meet at Neron 1.

On Mercer’s bridge, they are losing the battle with the Kaylon. Mercer orders an abandon ship. A Kaylon sphere makes a run directly at the Orville but suddenly everyone’s eyes go white for a moment and the action stops. Everyone except the first landing party members freeze too.

Talla stands up and transforms into a glowing humanoid being. She identifies herself as Denal.

Denal informs them she is a descendant of the residents of the multi-phasic planet Kelly was worshiped as a goddess on. They’ve evolved fifty thousand years in the two years since the adventure of “Mad Idolatry” happened.

They’re adventures were not hallucinations but custom-made experiences gathered from their minds. They wanted to experience death because they are now immortal.

Denal promises they’ll meet again and disappears. Mercer contacts LaMarr and informs him they’ll be returning to the ship right away.

Back on board, the team members share a drink and discuss death.