You gotta play the game more
Climb the pole and you will get a gold brick and a character.
You quit the game, click on 'New Game' from the menu and do it all again.
When you get a new gold brick, it will tell you how many you have out of a total of 200(including the one you just got).
Nothing, you just earn a gold brick. there are about 60 in all.
You have to get all of the gold bricks
unlock every gold brick in the entire game and you will unlock voldemort PLUS an extra level in diagon alley (when harry defeats voldemort in goblet of fire but roles are switched)
you collect 200 gold bricks
You have to get all 200 Gold Bricks to unlock him.
You only get him when you get all 200 gold bricks.
You Have To Unlock All Gold Bricks And Then Go To Borgin And Burkes !
You find all the ingredients to the potion that is in a gold cauldron by Harry's bed.