We hold the secrets.
Lets try to get everyone in one group.
Copies of the diary^
In order to join this group you must own at least one secret diary in your inventory.
In order to stay in this group you must keep at least one diary in your inventory. Therefore if you would like to sell diaries it's highly advised you look for extra copies.
From time to time I'll go through people's inventories to see if they still have one, if not I'm afraid it's a kick. Sorry.