One year prior to the events of Last Specter, Tony's father, Evan, died from falling off a cliff. Misthallery's police chief, Levin Jakes, ruled that Evan's death was suicide, along with support from the only eyewitness account made by Clark Triton. He too became reserved and bitter like his sister.
In order to protect Arianna from those who spoke ill of her, he disguised himself as the family's gardener and her carer, Seamus. Whenever he heard anyone badmouth her, he would paint the "witch's mark" on their house.
When Professor Layton, Luke, and Emmy, try to enter Barde Manor, they were turned away by Tony, who was disguised as Seamus. After they find the secret entrance and briefly speak with Arianna, Seamus finds them and orders them to leave the house immediately.
Later during the day, Layton, Luke and Emmy are told by Mimi that Seamus was seen going to the market by the canals in a boat. When they ask around, nobody says that they have seen him, but instead they saw a young boy, confusing Luke and Emmy.
Layton eventually works out that Seamus is actually Tony in disguise, and reveals this at the lakeside at Barde Manor.
Later on, when Descole's machine begins attacking Misthallery, Tony runs with his sister to safety. He too can be seen crying at Loosha's side in the Golden Garden when she dies.
Tony is last seen in the credits, taking his sister, Arianna, to see all townspeople celebrating her and Loosha's bravery.