After defeating the gym leader Brawly, the player must head north on Route 106, search for Steven and deliver the letter and to obtain TM47 Steel Wing. Along the way, the player will battle two fisherman, then speak to a hiker in front of a cave to obtain HM05 Flash. The player must teach the HM05 to a Pokemon to be able to navigate the cave to search for Steven.
There are several steps needed in order to search for Steven inside the cave to deliver the letter.
Inside the cave, the player must activate HM05 and then keep heading left up to the flight of stairs. The player then proceeds north until a fork in the path.
Going southward will lead the player to a slippery part of the cave where he or she will find the Everstone.
After obtaining the Everstone, the player travels north then head right until reaching a ladder. After climbing the ladder, the player heads left and follows the path to the next ladder.
After climbing the second ladder, the player heads left toward another ladder, climbs up that ladder, and then follows the path toward the door.
Once the player has delivered the letter to Steven and has received the HM05, the player goes up, then right, and then down the ledges to leave the cave.