You will obtain the Devon Scope from an encounter with Steven on Route 120. You can start the event with Steven immediately after you’ve reached Fortree City. And since this event is part of the main story, the Devon Scope is an unmissable key item.
You will need the Devon Scope to access the Fortree Gym, which is blocked by an invisible Kecleon.
Obtaining the Devon Scope (Step-by-Step)
The Devon Scope becomes available as soon as you arrive in Fortree City.
Here’s where to go to encounter Steven and get this key item:
Step 1: Head east from Fortree City’s Pokecenter and climb up the ladder to the right.
Step 2: On the upper platform, head east and cross the rope bridges.
Step 3: Keep heading east to cross the third and final rope bridge.
Step 4: After crossing the third rope bridge, climb down the ladder on the third and final platform.
Step 5: Once you get off the ladder, you will run into Steven.
Follow after him towards Fortree’s east exit, which leads to Route 120.
Step 6: On Route 120, head east and follow the dirt path.
Step 7: Keep following the dirt path towards the east, past the Parasol Lady. Wait for her to face the other direction if you want to avoid battling her.
Step 8: Still on the dirt path, turn south a few steps before the sign board and go into the tall grass.
Step 9: Make a beeline through the tall grass here. Use a Repel if necessary.
Step 10: You will soon reach a big wooden bridge at the end of the path. Head west and cross the bridge.
Step 11: Continue west on this bridge and you’ll run into Steven again.
Step 12: After a short dialogue, he will ask if your team is ready for a battle. Choose “Yes” to proceed.
Step 13: A wild Kecleon will appear and attack you. You can either knock it out, catch it, or simply run from the battle.
Step 14: After the fight, Steven will give you the Devon Scope as a gift.
Using the Devon Scope
With the Devon Scope in your bag, you will be able to access the Fortree City Gym.
Just walk up to the invisible Kecleon that’s blocking the path and use your Devon Scope. The Kecleon will run away once it’s revealed.
Tip: There are a few other hidden Kecleon locations that you’ll find throughout your OR/AS playthrough. So if you find yourself bumping into an invisible wall at any point, try using your Devon Scope to try clearing the blockage.