"Phone Home" begins with the young version of Ray Palmer running away from men in suits.
The Legends are gathered on the Waverider discussing potential teambuilding activities. When Mick is about to do a trust fall on Ray, Ray disappears. The group talks with Gideon who reveals Ray was killed as a child.
The group travels back to 1988 in order to stop Ray's death. They travel back to the day before he disappears as a kid, so the older Ray appears back on the Waverider.
The group gets outfitted in 80's gear to investigate Ray's death.
Mick and Jax are following a young Ray home from school and the kid stops at a newsstand, he's stealing candy.
Ray then heads home and is stopped by bullies as the older Ray, Nate, and Zari look on. Sara and Amaya drive around the block and say nothing is amiss.
The older Ray follows a younger Ray home and spies the younger version of himself feeding candy to something under his bed. After a moment, we see what the young Ray was feeding — a baby Dominator.
The group gets back together on the Waverider and they discuss what to do with the baby Dominator.
Jax approaches Stein about not helping the team out, he's suspicious the elder doctor is hiding something from the group. Mick pops in and tells Jax he has ways to get people to tell the truth.
Ray and Zari go into young Ray's house to find the baby Dominator. After looking around, they find the Dominator in a closet, but a young Ray can be heard in the background popping popcorn. Zari hides under the bed while Ray is forced to shrink down. The baby Dominator picks up a shrunken Ray and plays with it as a toy.
Young Ray and the Dominator are watching TV when Ray's mom comes home and yells at Ray for staying home and skipping school. When she hears a commotion in the closet, she almost discovers Ray's secret. Nate and Amaya run to the door and distract Ray's mom before she finds the baby Dominator.
On the Waverider, Gideon tells Sara and Stein that another time ship is approaching.
Ray packs up the baby Dominator and a shrunken Ray in his backpack and heads out to the woods and Zari follows in pursuit, trying to persuade a young Ray to hand them over.
With the help of Gideon, Mick tells Jax that's somebody has been sneaking off the Waverider to snitch on them to the Time Bureau.
While walking in the forest, Nate is trying to persuade Amaya to go back to where they were together and Amaya tells him they should just remain friends.
Sara is searching elsewhere when a full-grown Dominator shows up and knocks her out.
Mick leads Jax to a former storage room, one in which Stein has converted into a lab. They find that he's been working on a radio transmitter that covers space and time.
Zari finds young Ray and Gumball the Dominator hiding out in a fort and persuades them to walk out of the fort. As soon as they do, the men in suits arrive and administer drugs that knock them all out.
At the lab, Gumball's sedation is starting to wear off. The leader of the suits proceeds to instruct other agents to kill young Ray after they interrogate him.
On the Waverider, Mick and Jax approach Stein about snitching on the Waveride. Stein reveals that he left
Elsewhere, Ray grows back to normal size and him and Zari find a younger Ray and s save him from getting shot.
Sara wakes back up and radios to the rest of the group — the queen Dominator read her mind and knows where Ray's house is.
Nate is in the process of getting seduced by Ray's mom inside while Amaya stumbles upon a woman wrapped in a Dominator's web outside — it's the real Ray's mom. The person Nate has been talking to inside has been the Queen Dominator posing as Ray's mom.
Amaya rushes in the house to warn Nate and a fight breaks out. Nate and Amaya manage to escape and lead the Dominator on a chase through the woods.
At the rec center at the suit's makeshift lab, young Ray turns off the device blocking Gumball's abilities and Gumball makes the suits do a choreographed dance to 'Good Morning' from Singing In The Rain.
The two Rays and Zari meet Nate and Amaya in the forest and hand over Gumball to his mother.
Stein makes it back in time to witness the birth of his first grandchild and Jax takes a chance to apologize for thinking he was snitching on them.
Stein, Mick, and Jax celebrate with cigars.
Back in 1988, the Legends clear the mind of Ray's mother so she won't remember any of the night's events.
To make young Ray more comfortable with trick or treating amongst bullies, the Legends suit up in their uniforms and trick or treat with him.
On the Waverider, Ray and Zari play 'Two Truths and a Lie.' Ray leaves to go get some popcorn and is approached by Jax. Jax thinks Stein should stay at home with his grandkid and asks Ray to help "break up" Firestorm so it's possible for the two to be apart.