Post-Game - Pokemon FireRed and LeafGreen

Once you have defeated the Elite Four & Champion, you will wake up in Pallet Town and be able to talk to Professor Oak, who ask you to fill more of the Pokedex. You need to obtain 60 Different Types of Pokemon, then return to him and he will give you the National Dex.

Once have the National Dex, you will be asked to help Professor Oak and Celio on One Island; to do so, you need to travel to Vermillion City and use the ferry to One Island. Once you meet up with Celio, he will tell you that he is working on the Network Machine so you can trade Pokemon with trainers from Hoenn (Ruby & Sapphire) and Orre (Colosseum & Gale of Darkness), but he needs a special gemstone which is at Mt. Ember.

Once you reach Mt. Ember, go to the North East to find two Team Rocket Grunts, who you need to defeat. They tell you that there is the Team Rocket Warehouse, but you need two passwords, they will give you one half of the password "Goldeen need log". Afterwards, they will disappear and you can continue through Ruby Path: Continue through the tunnels, going down the ladders, when you get to the 3rd floor you need to take the South West tunnel down a ladder, you will then get to a room full of panels with Braille. Then go down the next ladder to the Ruby Room, collecting the Ruby. Once you have the Ruby, return to Celio.

Once you have given the Ruby to Celio, he will then ask you to get another special gemstone, he will give you the Rainbow Pass and tell you to visit Four Island. Travel to Four Island and you'll bump into your rival, he has nothing interesting to say, so move on to Icefall Cave in the North East of Four Island. Once inside the cave, surf to the next room and you will have to get through the easy ice maze. The ice is frozen, but walking over the ice will crack it, walking over it a second time will make you fall through.

First Optional Ice you need to take North Tile, then climb up the ladder. Then take the South Tile to get Sliding Ice, which you slide south ways to climb another ladder. You can then pick up HM07 - Waterfall. Then head back to the starting room, teaching one of your Pokemon Waterfall and climb the waterfall. In the next room you will find Lorelei fighting a couple of Team Rocket Grunts, defeat one of them and they will tell you that the Team Rocket Warehouse is on Five Island; however you need to find the second half of the password. So you need to travel to Six Island.

Once you get to Six Island, travel South towards Ruin Valley, travelling to the centre of the valley to get to Dotted Hole. You'll notice it's a fall puzzle, there is a stone in the middle of each for with a Braille Word telling you which hole to fall down. (Up, Left, Right Down) On the bottom floor there is the Sapphire, but a Team Rocket Scientist will steal it before you can collect it. He tells you the second half of the password "Yea, Nah, Chansey" for the Team Rocket Warehouse. You can now travel to Five Island

Once you have got Five Island, go to the Team Rocket Warehouse, defeating the Team Rocket Grunts on the way. Now you don't have to go through the Push Pads Puzzle but you can get a couple of neat items. On the other hand, you can go straight on to battle the two Team Rocket Admins, then fight the Scientist to win back the Sapphire. Once you have defeated the Scientist, he will return the Sapphire to you, which you can then return to Celio. Celio will fix it onto the Network Machine so you can trade between Hoenn & Orre. Doing this allows you to have the ability to now catch one of the three Legendary Beasts from Johto.

Celio