2. Use Surf north of Celestin City to make your way to Vermilion City.
3. In Vermilion City, defeat Lt. Surge and win the Thunder Badge.
4. From Vermilion City, head to Pewter City.
5. In Pewter City, use Rock Climb to reach the Pewter Museum.
6. In the Pewter Museum, talk to Celio to receive the Mystery Egg.
7. You can now continue your journey east toward Cerulean City where you will challenge the next gym.