He go's up the vent and into the attic .You need to goo outside and use the tools to break the bars on the window and go into the attic.
The inventor goes near Holmes (underground), so when you see pst... in here! or something like that,that's where the inventor is (this is main street for your information in poptropica).
He is in the air vents of the robot club.
The door code when chasing the inventor is 2014.
we wear it to look for the inventor
Go through a window outside of the club.
There is a window outside the building. It's hard to get to, though.
Go to the disco place, when you walk in go to items and use heat vision goggles. look strait up and he will be in the vents.
You do the window puzzle
When you complete all the game shows Holmes will tell all the robots to look for you. You walk into town and run to the manhole and jump down where you will find the inventor guy waiting.
game show island
go on to you tube for walk throughs. type in poptropica cheats, game show island. good luck!
find him