From the beginning, Percy Jackson and the Olympians has had a lot to explain. Backstories, Greek mythology, and the elements of the latter that author Rick Riordan changed to make this world his own all had to be conveyed to the audience in a way that was welcoming to newcomers and wasn’t a boring recap for fans of the books. For its first three episodes, Percy Jackson struck this difficult balance, but that changes this week. The gang’s train ride to Los Angeles in “I Plunge to My Death” is less than exciting, save for the final battle with the Chimera.

Episode 4 was always fighting an uphill battle: Percy, Annabeth, and Grover’s cross-country trek is an inherently slow and boring trip that Riordan smartly attempts to turn into a claustrophobic chase sequence with the help of this week’s villain: Echidna, the mother of monsters. But following the physical and psychological threat of Medusa, Echidna and the Chimera struggle to hit similar highs. Suzanne Cryer plays a good mom, but Echidna can’t instill the same fear as Medusa. It’s no fault of Cryer’s: Her character is never really given enough to work with, save for the moment she reveals who she is, and even then it’s done through dialogue – telling the audience to be afraid of her rather than showing us why we should be.

“I Plunge to My Death” falls into this trap too often. Conversations about Pan, Echidna, and Athena’s embarrassment over Medusa’s head being shipped to Olympus go on for much too long, unsuccessfully asking the audience to care about these relatively minor plot points. They’re important pieces of information to denote, but when the majority of the episode is spent explaining things to Percy, it doesn’t create intrigue the way it should. This dialogue-heavy attitude does lend itself to a few good character moments, however, as we see Percy and Annabeth grow a bit closer. Their midnight heart-to-heart toward the beginning of the episode and their commiseration over absent parents toward the end shows just how much the two demigods have in common, and how far their relationship has come in such short time.

When “I Plunge to My Death” finally breaks away from the conversation, it’s able to find the fun. Percy’s fight with the Chimera is an exciting climax to the episode, giving Percy a big hero moment as he “sacrifices” himself for the greater good of the quest. It also serves as an intriguing midseason finale, with the “big reveal” moment of Poseidon saving Percy, and a callback to the episode’s opening scene as he learns he can breathe underwater. It sets things up for what will undoubtedly be a very different second half of season 1, splitting up our heroes and taking things deeper into the mythological world. And the flashback to Percy’s swimming lesson bookends things nicely with a lesson about trust, while continuing to ground the story in Percy’s love for his mother – and hers for him.