I don't think you need it but it is in Esmeralda City with the hiker
Where Is Flash In Pokemon Light Platinum?
From someone in the town where the second gym is.
Theres a guy near the pokemon center talk to him you need it to get to the 8th gym
Pokemon light platinum cheats code
Go to Lost hill and watch THE HIKER SAY "What a good day!
There is a hiker who will be roaming