Percy Jackson and the Olympians episode 4 recap and ending explained: 'I Plunge to My Death'

Percy, Annabeth, and Grover take a visit to the Gateway Arch in St. Louis in the fourth episode of Percy Jackson and the Olympians, but it's no field trip.

Suzanne Cryer as Echidna in Percy Jackson and the Olympians. Image: Disney+.
Suzanne Cryer as Echidna in Percy Jackson and the Olympians. Image: Disney+. /
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In the third episode of Percy Jackson and the Olympians, Percy, Annabeth, and Grover escape several monsters, including Alecto and the Furies (again!) and Medusa. Percy ships Medusa’s head to Olympus via the Hermes Express, and we get our first look at Lin-Manuel Miranda as the Messenger of the Gods. Unfortunately, Percy and the gang ain’t out of the woods yet. 

“I Plunge to My Death,” the fourth episode of Percy Jackson and the Olympians, begins with a flashback of Sally Jackson urging Percy to learn how to swim. Little Percy doesn’t want to do it. Then, the vision shifts to the desert, again, and Percy is all alone. The Voice is back, and it warns Percy that a Forbidden Hero attracts doom and “she is coming.” That’s quite ominous. 

Percy wakes up, and finally, after three episodes, Annabeth and Percy have a moment where they aren’t at odds or feuding. Percy asks Annabeth about Thalia, and Annabeth opens up about Thalia and her past, which is a sore spot given what happened. This is one of the first conversations where Percy begins questioning the Gods, his place in the world, and the way that the Gods withhold love. It leads Annabeth to tell her story and truth for the first time. 

She reveals that she was a gift to her father from Athena, and for a while it was great, but then her father married another woman and they had kids. Annabeth was pushed out at 7 years old, and she left home. She urges Percy to reconsider his stance about the Gods. You know what you’re going to get with the Gods, after all, she says. 

Percy, Annabeth, and Grover are on a train for Los Angeles. The cross-country trek is back on, but trouble is near. While riding the train, the trio are questioned by the police. Someone destroyed a train cabin and a woman, played by Suzanne Cryer, alleges that Percy, Annabeth, and Grover are the ones responsible for such destruction. 

It was not this trio, but someone or something tore the train cabin to shreds. It looks like that someone or something was looking for something, potentially Zeus’s Master Bolt, which some in Olympus and elsewhere believe Percy stole. 

This mysterious woman has a conversation with the heroes, and she reveals that she is the “Mother of Monsters,” also known as Echidna. She’s brought a “little” monster with her in a carrier for a small chihuahua, but it isn’t a chihuahua! 

Echidna reveals that she has been stalling for her little monster to pick up their scent. “You should run now,” she says as a  giant tentacle shoots out of the carrier and stabs Percy. Annabeth stabs the monster. The trio flees, but this is not over. I guess it’s never really over, you know? 

I just have to say that Cryer is so menacing in this role of Echidna. For a kids' show, Percy Jackson and the Olympians plays it pretty chill with the scares. But, Echidna is the stuff of nightmares. Her calm is so wicked and terrifying to me, an adult. It’s perfect! 

After escaping the monster and the train, Annabeth makes the group take a pitstop at the Gateway Arch in St. Louis, Missouri. It’s a tribute to Athena with such a glorious architectural design, but it’s also supposed to keep them safe from monsters. Athena will protect them in the arch, or so they think. 

Percy and Annabeth have another conversation about being children of the Gods. Percy is upset that his father never chose to have a relationship with him, while Annabeth is also struggling with that with her mom, but they’re choosing to handle it differently. Percy isn’t ready to forgive. He does want to forgive his father. He says Annabeth has helped him more in a few days than his father, while Annabeth chooses to believe that in some way her mother cares for her. 

Episode 4 ending, explained

Percy suddenly collapses. Those stingers from the creature were poisonous! They dump Percy in the fountain, but the water is not healing him. They must go to Athena’s altar at the top of the arch so Annabeth can ask her mom for help, but Echidna and her monster close in. 

At the top, Annabeth and Grover realize Echidna has the Chimera, the demigod killer with her. That’s what the monster is. For them to stand a chance, they need to split up. Annabeth pulls the fire alarm to save all the humans. She sends Percy down the stairs to fight the Chimera alone. She makes Percy promise he’ll continue the quest to find Zeus’s bolt and visit the Underworld. 

Percy gives her Riptide to protect herself, but when she reaches for it, Percy pulls Annabeth behind the door, trades places, and then locks the door. He faces the Chimera at the top of The Gateway Arch while Echidna watches. 

Percy dodges the Chimera’s fire, but Echidna opens a hole in the arch and Percy falls through. He’s dangling above the ground and falls. Somehow, a wall of water rises out of the Mississippi River and pulls Percy under. It was Percy’s father, Poseidon, through the help of a Nereid. She begs Percy to breathe under the water, which he finally does by the episode’s end. 

So, the episode begins with Percy struggling to swim with his mother, and it ends with Percy accepting his fate and breathing underwater with his father! Well, his father’s power. 

Percy, thankfully, will be healed by the waters of the Mississippi River. In the preview for the fifth episode, we see Percy reuniting with Annabeth, but we also see The Fates with their knitting string and our first look at Ares (Adam Copeland). Well, well, well. 

This is an incredible episode, and it just might be my favorite so far. I know we didn't get a full battle, but we're getting incredible performances from this cast. This is the third episode in a row where the actress who plays one of the monsters has delivered. Cryer is so good as Echidna. I have a feeling we haven't seen the last of her yet. This whole cast, though, is phenomenal.

In the fourth episode, we start to see the foundation of Annabeth and Percy's friendship. We know this is a friendship that will last from the books, but seeing it play out episode by episode is interesting. For the first two episodes together, they were very much at odds, but in this episode, Percy admits he trusts Annabeth and respects what she brings to the table. You have to start somewhere!

The fifth episode of Percy Jackson and the Olympians, “A God Buys Us Cheeseburgers" hits Disney+ on Tuesday, Jan. 9, 2024, at 6 p.m. PT and 9 p.m. ET. 

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