Marissa Fittes, is the founder of Fittes detective agency -the biggest psychic agency in the country.
In her youth, she was the first person to discover the Problem in Britain, alongside her partner at the time Tom Rottwel, (50 years before the events at Lockwood & Co) in Kent where the Problem first started.
Marissa is considered a hero against the epidemic of ghosts plaguing the country. She wrote Fittes Manual for Ghost-hunters which all agents use and carry around. She was a skilled listener and is the only known person, besides Lucy Carlyle to talk to a type three ghost.
When she died the agency passed over to her daughter Margret, who was a quiet reserved person. Margret died 2 to 3 years after inheriting the Fittes Agency. It was passed onto Marissa's granddaughter Penelope Fittes.