On the lonely island there is a secret pass near the volcano itself although you'd have to be very brave or clueless to find this for it is a hidden entrance to the headquarters of Team Magma!
As you get to the island you are asked multiple riddles by a stranger when you get here you will find out the riddle master is actually in fact the gym leader Blaine. Be careful for even though it doesn't looks like he has a building for a gym he uses the sleeping Volcano as his gym arena so be very sure you have good water pokemon to counter his fiery hot pokemon. If you are successful you will recieve your next prize the Volcano Badge!