Sonic 3 & Knuckles Part 11: Hidden Palace Zone (Hyper Sonic & Tails)

Hidden Palace is the first zone of Sonic 3 & Knuckles to be a single-act zone. It's completely different from the Hidden Palace that was meant to appear in Sonic 2. Sonic 3 & Knuckles' version is the original location and home to the Chaos Emeralds, the Super Emeralds, and their powerful superior, the Master Emerald.
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There's a secret area here that only Tails could reach that has all of the powerups. I decided to take some time to use Tails as Player 2 just to show this. There were some monitors on the other side, but I forgot about them.
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Hidden Palace is where the biggest, literally speechless plot twist appears. Sonic & Tails confronts and fights Knuckles here. He's programmed differently from all of the other bosses, but he still goes down in 8 hits like an Act 2 boss.
In fact, you don't even have to jump at him. Just overlap his space with Hyper Sonic and he'll get hurt. You may also want to take a good look at the mural that hangs above you during the fight with Knuckles. Could it be foreshadowing events that have yet to happen? Of course it is!
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When Knuckles is defeated, he notices some commotion to the right and heads there. Follow him.
It shows us the Emerald Shrine Sonic was at before when he was getting all of the Super Emeralds. Dr. Eggman appears and steals the Master Emerald right from its perch. Knuckles then realizes who his true enemy is, and tries to take the Emerald back, but Eggman electrifies him into unconsciousness.
Sonic, Tails, & Knuckles fall into a different secret area, one that Knuckles knows of. He wakes up to lead Sonic & Tails to another teleportation platform. Right before he jumps in, you can see that Knuckles is exhausted after being literally shocked by Eggman's attack.
And... Maybe also because of the beating Sonic gave him earlier.
The teleporter then takes what could now be known as "Team Sonic" up into the clouds, way above Angel Island itself to a site known as Sky Sanctuary.
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In a secret Zone Select screen, Hidden Palace is listed as "Lava Reef 4". The reason for this is because Lava Reef's Act 2 boss has its own listing at "Lava Reef 3", so this was to even it out a bit.
The song of this zone is just the same one as Lava Reef's Act 2 theme. I think this is because of how much different the Act 2 remix of Lava Reef is to Act 1's theme compared to all of the other Act 2 themes of the other zones.
I think it's also because Hidden Palace is still closely-related to Lava Reef than any other zone has with each other. How does a valley like Marble Garden seamlessly link to a place like Carnival Night, again?