TMX8 Flash

==Information==
Location: Underground Railnet
Available: After Badge 03
==Guide==
Go to the left entrance of the Obsidia Slums. Go to the lower escalator on the right side.
Go down the escalator and go into the right area. Use Rock Smash to break the rock.
Use Rock Smash on the hole and go inside. Go all the way to the end and turn left. You should also press the switch near the gate for easier future access.
Go straight left until you reach the stairs. Go down to the bottom of the stairs. Break the hole closer to the stairs, or to the right of the train, in other words. 
After the restoration of Reborn, if you donate to the Railnet Reconstruction Project, the whole Underground Railnet area, along with its items, will be inaccessible. In that case, you can get this TM in the Lost and Found counter of the Underground Railnet. The counter can be reached from the rails going to Opal Ward from Lower Peridot Ward.