You’ll get the Letter from Mr. Stone in Rustboro City. He’s the president of the Devon Corporation, and he’ll give you the letter as a key item to deliver to his son Steven.
You can deliver the letter to Steven once you reach Dewford Town and defeat Brawly for the Knuckle Badge. After winning the badge, head north-west of town to find Granite Cave. Steven will be located in a room at the very end of Granite Cave.
It’s worth mentioning that the letter is part of a longer questline in ORAS, which also involves the Devon Parts.
But before you can even obtain the Letter from Mr. Stone, you must have completed these requirements:
- Defeated the Rustboro Gym and obtained the Stone Badge from Roxanne.
- Recovered the Devon Parts from the Team Aqua (AS)/Magma (OR) grunt inside Rusturf Tunnel.
Obtaining the Letter (Step-by-Step)
Exit Rusturf Tunnel after recovering the Devon Parts. Make your way back to Rustboro through Route 116. You will enter the city from its northeast.
Step 1: Following the main street, head left from the northeast.
Step 2: Keep following the main street and heading left. Turn south at the corner.
Step 3: Head down the main street, then turn left at the crossroads in front of the Gym. The Devon employee will be waiting for you just outside the company’s building.
Step 4: The events will happen automatically from this point. Following a short scene, the Devon employee will take you inside the building.
He will then introduce you to Mr. Stone, the Devon Corporation’s president.
Mr. Stone will hand you the Letter and ask you to deliver the item to Steven in Dewford town.
Delivering the Letter to Steven (Step-by-Step)
To deliver the Letter, you must first beat the Dewford Gym. You can proceed with the Letter questline as soon as you obtain the Knuckle Badge.
You will find Steven inside a room in the depths of Granite Cave. The cave itself is located at the end of Route 106, to the northwest of Dewford.
So here’s how you’ll find Steven and give him the letter:
Step 1: Exiting the Dewford Gym and start heading north out of town.
Step 2: Keep heading north until you arrive at Route 106.
Step 3: From Route 106, turn left at the shoreline and start heading west.
Step 4: Keep heading left until you see a small boulder. The entrance to Granite Cave will directly ahead.
Step 5: Inside Granite Cave, turn left from the entrance and follow it all the way down.
Step 6: Keep heading left until you arrive at this set of stairs at the end of the corridor.
Step 7: Head down the stairs until you reach the deepest part of the cave.
Note that the hiker isn’t a trainer. You can actually speak to him to obtain TM70 Flash.
Step 8: Enter the room and head towards the staircase in front of you. Eventually you’ll trigger a short cutscene.
Steven will then introduce himself. You will hand over the Letter after a brief dialogue, completing the quest.
Steven will also give you TM51 Steel Wing as a reward.
Once you deliver the Letter, the main story will advance from here.
So you can now proceed to Slateport to deliver the Devon Parts.