After you go north through the tree-lined Palais Lane, you reach Parfum Palace to find out about the Poké Flute.
If you go to the southeastern corner of the area, you find a Photo Spot. Check on the sign to call Phil the Photo Guy. If you ask him to take a picture, you'll stand in front of the palace and can use the camera controls on the touchscreen.
Pressing the R button takes a photo. You'll be asked if you want to save the photo that you just took. You can zoom in by pressing right on the +Control Pad, or zoom out by pressing left on the +Control Pad. Press the A button to switch to manual mode.
In manual mode, you can adjust the focus by pressing X, adjust the exposure time by pressing Y (shorter exposure time creates a darker picture but with less chance of blur, while longer exposure time creates a brighter picture with more chance of blur), and change the depth of field with the slider above the eye (depth of field affects whether everything is in focus or only things at a certain distance are in focus).
Near where you entered the Parfum Palace area, talk to the woman in green to receive an Oran Berry.
In the northwest of the grassy area in front of the palace, you find an Ether.
Walk toward the gate. The man standing next to the gate will stand in the way. Shauna will arrive. The man asks for 1000 Pokédollars per person to enter the palace. Shauna objects to the owner's attitude that one can never have too much money. The gate guard says that the money "probably" is used to help maintain the palace. You and Shauna pay the fee. Go into the palace.
Inside, a man runs around saying that he can't find his Furfrou. Shauna will say you should help him look.
To the left of the room where you entered the palace, there is a backpacker in front of a door. You can go into the room and sleep in the bed to heal up.
Upstairs, in the west wing, there is a library. The books on the shelves on the left mention an incident in Shalour City that seems to have something to do with Mega Evolutions. In this room, there is an Amulet Coin sitting in front of the fireplace.
Go to the ground floor of the palace and go through the big double doors in the middle. You'll enter the garden. Walk along the bridge. Shauna will come out and go to the back of the garden to look for the Furfrou.
In the southeast area of the garden, go to the middle of the shrub area to find an Antidote just above the center of the shrubs.
In the southwest area of the garden, go toward the middle of the shrub area to find a yellow pokéball that contains HM01 Cut. Teach this to a pokémon and it can cut down prickly thorn trees. In the northwest of this shrub area, there is a Super Potion.
In the far northwest corner of the garden, there is a Guard Spec.
Go into the northwest shrub area to find the Furfrou. It runs away. Shauna suggests that the two of you try to corner Furfrou into the dead end in the middle of the shrub area. As you walk around the garden, you might see Furfrou. If you go close to it, it will run away. Walk to one of the spots that Shauna said she should stand, then talk to her. She'll wait at that spot.
Have Shauna stand in the bottom middle of the shrub area, where you first saw Furfrou. If Furfrou is there, just walk up to it to make it go elsewhere. When Shauna is standing in the bottom middle of the area, approach Furfrou from the left or right. Furfrou should run toward the back of the garden. Go talk to Shauna and have her stand at the crossroads that Furfrou just ran away from. Then go to the opposite side of the garden from where Shauna is standing, then go up. Approach Furfrou. It will go into the dead end and you and Shauna will catch it.
The Furfrou's owner will come up. He will decide to put on a fireworks display to celebrate his reunion with his Furfrou. I guess he must own the palace! He says to go up to the balcony on the second floor of the palace to watch.
Go back into the palace and go upstairs. Go to the middle area and use the northern doors to enter the balcony. Talk to Shauna and she will have a heart-to-heart talk with you. Then the fireworks will start.
After the fireworks, the owner of the palace will arrive. Shauna remembers about the Poké Flute, so ask about it. The owner will agree to get it, but will explain that he took the flute as a payment for a loan from the owner of Shabboneau Castle, whom the owner refers to as "a common person". You'll get the Poké Flute. The owner reminds you to always return what you borrow.
After the owner leaves, the butler mentions books in the library that refer to Mega Evolution. He also gives you TM17 Protect.
Shauna says that you should return the flute after you wake up the Snorlax.
Go back to Palais Lane. If you enter it from the left side or the right side from Parfum Palace you can explore the parts that were inaccessible before. For more information, see Palais Lane East and Palais Lane West.
Go south from Parfum Palace, then west along Rivière Walk to get back to the sleeping Snorlax. Give the Poké Flute to the black belt and he will wake up the Snorlax, but it will attack you. In the battle, you can catch it if you wish, or just defeat it, but keep in mind that this Snorlax is the only one that you will encounter in the game, and you can't encounter Munchlax either.
Afterward, the owner of Parfum Palace will let the black belt keep the Poké Flute, but tells him that he needs to practice because he was better at it when he was little.
Now that the Snorlax is gone, you can visit the west side of Rivière Walk.