National Park and the Bug-Catching Contest
The road to Ecruteak City, your next destination, is a long one so head out of the Goldenrod City gym with your new Plain Badge and head to the city's flower shop. The shopkeeper gives you the squirt bottle item, which is necessary to get past an upcoming route. Make sure your Pokemon are healed and you have plenty of Poke Balls, because you're about to encounter a rare Pokemon.
Once you're ready, take the city's north exit to reach Route 35. Route 35 is short and straightforward, but hosts nine trainers to battle, including two pairs of team-battles, so it will likely take you a while to get through. Backtrack to Goldenrod City to heal as necessary, and eventually make your way to the northern end of Route 35 where you'll find a building, the entrance to National Park. National Park hosts a bug-catching contest on Tuesday, Thursday, and Saturday. You have a set amount of steps to wander through the park catching a bug Pokemon. You can only bring one partner Pokemon and can't use any healing items. You can only capture one bug Pokemon at a time as you're forced to release one if you catch another. At the end of the contest, the trainer with the best bug Pokemon (based on level and rarity) wins a prize, plus gets to keep their Pokemon. Rare Pokemon like Scyther and Pinsir can be found here.
Sudowoodo and Route 37
You can get to Route 36 either by passing through National Park or by taking the east exit (blocked by a tree you can cut down) from Route 35. Either way, you'll want to head east until you find your path impeded by a strange-looking tree. This is Sudowoodo, a rare rock-type Pokemon. Use the squirt bottle to wake it up and it will attack. Here you can either capture or knock out Sudowoodo to clear the way. Capturing it is your best option since it's such a rare Pokemon.
With Sudowoodo out of the way–or in your party–continue north to reach Route 37. You may also opt to head east, which leads you right back to Violet City and provides an easy route back to Azalea Town if you'd like Kurt to make a Poke Ball for you. Once you reach Route 37 you'll find two sets of team battles and individual trainer waiting to battle you. Also, the east end of the route features a small grove of Apricorn trees–another great reason to head back to see Kurt. When you've beaten the trainers and you're ready to move on, head north into Ecruteak City.
Legendary Pokemon Suicune, Entei, and Raikou
When you first enter Ecruteak City, its Pokemon gym lies two buildings to the west. When you try to go in, you'll be told Morty has gone to the Burned Tower so you can't challenge him. It seems like Pokemon gym leaders are almost never where they're supposed to be, so head to the northern end of town and enter the ruined remains of Burned Tower.
Inside you'll find Morty and his friend Eusine, a hunter of legendary Pokemon. They're searching for legendary Pokemon that supposedly dwell in Burned Tower so Morty isn't ready to accept your challenge just yet. You can wander around the upper floor of the tower to battle trainers and collect a few common–but useful–items, or take the ladder down to follow Morty and Eusine.
Downstairs you'll find Morty and Eusine staring at the three legendary beast Pokemon: Suicune, Entei, and Raikou. The legendary Pokemon look at you and then take off. Eusine says he has to continue his hunt while Morty says he'll be waiting for you at the gym. After they leave, Rival shows up to do battle. This time he's got a level 20 Gastly, level 20 Zubat, level 18 Magnemite, and level 22 Quilava (or Croconow or Bayleef if you chose Cyndaquil or Totodile as your starter). Once again he takes off in a huff, and now you're free to leave and challenge Morty.
Pokemon Gym Leader Morty
Pokemon gym leader Morty and his four underlings use pokemon of the ghost type, and his gym is suitably dark and eery. The entire gym is shrouded in darkness and consists of a narrow, rocky pathway. If you fall off to either side you'll have to start back at the beginning of the gym. Follow the lamps marking the way to stay on the path. Each lamp also marks the location of one of Morty's trainers. When you reach the fifth one, you've found Morty himself.
Morty's team consists of a level 21 Gastly, level 21 and 23 Haunters, and a level 25 Gengar. Ghost Pokemon can't be harmed by normal physical attacks (anything like tackle or scratch, for instance), but they are extremely weak against dark- and psychic-type moves. Use these to defeat Morty and earn yourself the Fog Badge. It lets you control Pokemon up to level 50 and use HM03: Surf outside of battle, which will be essential in the next part of our Pokemon Soul Silver walkthrough.