Ben je goed in Engels? Ik ben te lui om het te vertalen. 
''The entrance to the common room is located "in a nook on the right hand side of the kitchen corridor", concealed behind a stack of barrels. In order to reveal the entrance, no password is required. Instead, one must tap the barrel two from the bottom, middle of the second row, in the rhythm of ‘Helga Hufflepuff’, which will make the lid swing open, exposing a passageway that will lead to the basement when crawled through. If either the rhythm of tapping or the lid tapped is wrong then the intruder will be doused in vinegar and barred access.''
Great minds think alike.