The cupboard is a piece of scenery located in the White Knights Castle that contains a Portrait of Sir Vyvin's father holding the Faladian sword. During The knight's swordquest, players must retrieve the portrait from the cupboard so that Thurgo can use the Portrait to create a duplicate of the Faladian sword. In order to successfully open the cupboard, another player must first distract Sir Vyvin by talking to him.
It is still possible for players who have completed the quest to fail searching the cupboard if Sir Vyvin is not distracted.[1] This is of no consequence to the player and is only noted here for documentation. If the Knight is distracted and the quest has been completed, the player will receive a message when searching the cupboard: There is just a load of junk in here[2]