Percy Jackson & the Olympians S2E4 Ending Explained: Thalia’s Fate, Annabeth’s Dark Past, and a Cliffhanger That Changes Everything

Season 2 finally hits the gas. Percy Jackson & the Olympians S2E4, 'Clarisse Blows Up Everything', drops today (December 24, 2025) on Disney+, and it actually lives up to the title. We pick up right after the speedboat escape from Luke's ship and barrel straight into Annabeth's past, Thalia-sized heartbreak, and a nasty run at Scylla and Charybdis. Yes, we are finally headed into the Sea of Monsters.

Where we left off

Percy, Annabeth, and Tyson literally blew past Luke last week. This hour pivots hard from running to reckoning: Annabeth goes back to one of the hideouts she used with Luke and Thalia, Clarisse corners the trio with her undead battalion, and everyone ends up on the same doomed ship playing chicken with ancient sea nightmares.

Annabeth's past, finally spelled out

Back in that old tunnel, Annabeth finds a lost bracelet and the memories hit. Young Annabeth was there with a guy named Tyler, who handed her a charm bracelet supposedly from Kellogia, the goddess of stealth, and told her if she wore it and hid, monsters could not find her. That stealth-goddess detail is a new wrinkle, and it is... an interesting one.

'They have been found.'

Thalia bursts in with that warning. Turns out Grover had tracked them down on Chiron's orders to bring the kids to Camp Half-Blood. Luke and Thalia wanted none of it, citing their history with the camp, but Grover still got them to a satyr hideout with a protective circle around a tree. Luke planned to bail at sunrise with just the three of them, leaving Grover behind. Then Annabeth realized the bracelet was gone.

That night she stepped outside the protective circle to look for it and got grabbed by three Cyclopes. Thalia saved her, but the scare forced a decision: Thalia told Grover to take Annabeth to Camp Half-Blood because she was not safe on the road with them.

In the present, Annabeth adds the part she never really talks about: on their approach to camp that night, Furies attacked. Thalia stayed behind to fight and told the others to run. That was the last time Annabeth saw her. The show does not show the death, but the implication is clear — Thalia died holding the monsters off, and Zeus later turned her into the pine tree that protects the camp. It also explains Annabeth's guilt and why she clashed with Percy about killing Luke in episode 3; those bonds were real.

Clarisse shows up, and the negotiation gets bloody

On an island stop, Clarisse arrives with her undead crew and demands the coordinates to the Sea of Monsters. Annabeth bargains: take us into the Sea and we hand over the numbers. She even makes the case — Tyson knows engines, and Percy, as Poseidon's kid, is basically a built-in navigator. Clarisse refuses and threatens force. Percy throws out a trial by combat. Clarisse counters that she has three crewmembers who can already do everything the trio is offering.

Annabeth answers with action. She uses that stealth edge to quietly take out those exact three undead in the scrap. No living casualties, and, well, the victims were already dead. Out of options, Clarisse agrees to team up, and everyone sails out together.

Two bad choices: Scylla or Charybdis

At sea, Annabeth lays out the only two routes: hug the cliff with Scylla (the tentacled terror) or aim for Charybdis (the giant whirlpool). Percy votes Scylla. Clarisse says Charybdis, because her ship has a cannon loaded with celestial bronze — the monster-piercing stuff — and a whirlpool looks like a stationary target. The snag? Scylla perches on a cliff, out of cannon range.

Annabeth drops a grim history lesson: Odysseus chose Scylla because she always takes six — fixed casualties instead of total annihilation. If six of Clarisse's undead tie up Scylla, the rest might slip through. Clarisse hates the idea because she promised her crew Elysium, not another death. Later, the dead men volunteer anyway.

Scylla, Charybdis, and an explosion

Scylla hits first. Two undead are snatched instantly. Clarisse cannot watch more fall and swings toward Charybdis. The whirlpool starts shredding the ship. The cannon does nothing. Control is slipping.

Percy tries to raise a wave and redirect them back toward Scylla. He calls for Hermes's wind-filled thermos to juice the maneuver, and Annabeth hustles to grab it — only to lose it when a surge of water blasts through and knocks it into the flooding lower deck. Seconds later, the boiler room explodes with Tyson still down there. Instead of sinking, the ship blasts straight up into the air. Smash to credits.

Where that cliffhanger leaves everyone

• Is the ship actually intact after that vertical launch?
• Tyson's fate after the boiler-room explosion is unknown.
• Hermes's thermos is somewhere in the bowels of a half-drowned ship.
• Clarisse's alliance holds for now, but losing volunteers and switching to Charybdis mid-run is going to have consequences.
• Annabeth's past is out in the open, which is bound to shape whatever calls she makes next.

It is a real turning point, and the action finally matches the stakes. Percy Jackson & the Olympians Season 2, Episodes 1–4 are now streaming on Disney+ (US).