Chief Thief Robin is a member of Lumbridge's Thieves' Guild and second-in-command there. When met, he'll tell you to speak to his boss Darren Lightfinger. In his life prior to the Thieves' Guild, he was a poor man living in Lumbridge. After he joined the Thieves' Guild he started stealing from the rich.
Buyers and Cellars[]
During the Buyers and Cellars quest, Robin is your main contact person, giving you information on the owner of the chalice and how to steal it.
Trivia[]
His name is a reference to Robin Hood, a thief who stole from the rich and gave to the poor in English folklore. He also states that he stole from the rich to give to the poor, namely himself.