v-gamer

Best answer as chosen by Asker / Ratings
Alright, now that you've obtained the first four badges, talk to the Galactic grunt in the northeast corner, facing the building that leads to the Safari Zone. Start chasing him to battle your rival. Once you beat him, continue following the grunt and you'll eventually battle him. Once you beat him, go up a bit and talk to Cynthia. She'll give you the secrepotion to give to the Psyduck on Route 210. So, go there and give them the secretpotion, and Cynthia will come up again, and gives you the Old Charm, which she asks that you give to her grandma in Celestic Town, which is just beyond the northern part of Route 210 - which you just accessed. You might need HM05 Defog, which is given to you by one of the guys near the entrance in the Safari Zone in Pastoria City, to get through Route 210. Once you do, battle the grunt in front of the cave, and once you beat him, an old woman will come up and recognize the Old Charm, admitting she is Cynthia's grandma. After you give her the Old Charm, go in the cave and examine the back wall. Once again, she comes up and gives you HM03 Surf. With this, you now have access to the fifth gym in Hearthome City, and continue the storyline.