Captain Rovin is a prominent captain of the Varrock guard. He takes his job very seriously, questioning players for entering restricted areas. Players can also choose to tell him about the castle's ale delivery, in which case he will direct them to the kitchen staff.
The captain can be found on the 2nd floor[ of the northwest tower of the castle, at the top of a spiral staircase. But other than ]quests and dialogue, he has no use.