Pitts was a physician which Robin's band enlisted to help Marian after she was stabbed in the guise of the Night Watchman by Gisborne. Unbeknownst to the gang, Pitts was in the employ of the sheriff, and left a trail of bandages from Nottingham to the cave where Marian lay near death. Then, instead of assisting Marian, Pitts drugged her so that the band believed she was dead, then sneaked out to collect his reward from Sheriff Vaisey. Out of cowardice, he pleads with Sir Guy not to kill him. Robin saw the bandages and realized Pitts' betrayal. He went after him, only to see Vaisey order his men to shoot him in the back after he received his payment.
Pitts' role, while limited, comprised two episodes of the season one finale, "The Return of the King" and "A Clue: No".