If you're playing S3&K as Tails, or have him with you as Sonic, one of the hidden areas in Sonic & Knuckles that make use of his ability can be found right here in the palace. On the second floor up, just before the small internal room with the first transportation device, stand to the left of the spikes in front of the entrance to the narrow corridor, at the top of the steps. Jump up nice and high from the top step and take flight, and keep going higher and higher into the large, wide space above you between two purple pillars. Keep ascending and stay as close as you can to the left pillar, and you should just barely be able to make it all the way up to a hidden ledge at the top. Head left from there and you'll find six item boxes; One ten ring, an invincibility, a speed-up and one of each of the three shields. But wait, there's more! Fly over to the slightly higher ledge at the top of the right pillar to find an additional 20 rings and an extra life. It's a power-up jackpot!

To make no effort in avoiding rather tired Sonic dialogue cliches - Playtime is now over. Sonic runs into Knuckles and he's not happy. Every single trap Knuckles has thrown at him has failed to keep the 'hog down, and now that he's so close to the Master Emerald, Knuckles can no longer afford to hold back. He's convinced that's what Sonic is after, but it'll have to be over his dead echidna body. It's come down to this. What we've all been waiting for, in the room just before the shrine to the Master Emerald; Sonic vs Knuckles!...

Unfortunately, that turns out to be a bit of an anti-climax, as this character fight is a pretty darn easy one. Then again, most are, but of course this is the very first of its kind. Knux will stand there with his fists up, occasionally punching air. All you have to do is hit him on the head at every opportunity, of which there are plenty. One advantage the spiny marsupial has up his sleeve is the ability to block Sonic's most prized attack, the spin dash. Avoid using it, as the only effect it has is to knock him backwards a little way, which isn't really that helpful. Instead, go for the standard jumping spin attack and aim for his head, whenever he's just standing there, punching air. Knuckles' main attacks include a spin dash of his own (which does hurt you) across the ground or a jump and glide attack across the air, and he usually goes into one of these just after you hit him, or between long pauses of nothingness. The glide can be tricky because you can hurt him during this attack, by landing a hit just about anywhere on him, but you also need to watch out for his fists, as they'll hurt you too if you jump into them. Oh and Take a look at that mural painting in the background when you get a chance. It may make more sense to you later on in the game...

Sonic enters the shrine, with the Master Emerald sitting at the top among some crystals, and the holders for the seven Chaos Emeralds around it (filled with however many you've managed to obtain in the Special Stages so far). Knuckles is standing in the middle shaking his fist up at something. Sonic looks up to see a robotic arm coming down from the top and grabbing the Master Emerald! It's Dr. Robotnik. That Master Emerald is now the only thing needed to re-power his Death Egg and launch it again for a third time, and he doesn't care what happens to Angel Island in the process. Knuckles has been betrayed by his ally, and now it's clear; Eggman tricked Knuckles into defending the Master Emerald from Sonic, when really, the only threat was from Eggman himself, who could now sneak into the Emerald chamber while Sonic and Knuckles were busy destroying each other, and make his move on the powerful stone.

In the Egg-mobile (with a large robotic grabbing attachment underneath, holding the Master Emerald), Robotnik begins to exit stage right, but not if Knuckles can do anything about it. He desperately tries to stop the doctor by launching from the altar and hitting him, as Sonic follows on the floor below. Over on the far right side of the room, you have complete control over Sonic again and can hit Eggman yourself as much as you please, but it'll do no good. Willing to risk his life for the Master Emerald, Knuckles grabs onto it in an emotional display. Realising he has a nagging problem here, Eggman stops and pulls out two snaking electrical wires. These connect with Knuckles and give him a nasty bolt of electricity, which knocks him off the emerald and down to the floor below. Finally gaining a victory, Robotnik flies away. Sonic goes after him, but then stops and turns to Knuckles, who's laying unconscious on the floor. At that moment, the floor beneath them inconveniently gives way and both characters fall down a long, vertical shaft to some steps at the very bottom. Knuckles is still laid out, but quickly comes to. There's a barrier on the left that you can't break, but Knuckles will get up and do it for you with one punch. Follow him into the next room where there's another teleporter device awaiting. Knuckles is weak from the shock, but now the two are going to have to work together in order to get the Master Emerald back, save Angel Island and destroy the Death Egg once and for all! Knuckles jumps into the teleporter and Sonic follows, which leads them up to the floating ruins of the Sky Sanctuary Zone...