Warning - this story contains distressing content and discussion of suicide
Megan Garcia had no idea her teenage son Sewell, a "bright and beautiful boy", had started spending hours and hours obsessively talking to an online character on the Character.ai app in late spring 2023.
"It's like having a predator or a stranger in your home," Ms Garcia tells me in her first UK interview. "And it is much more dangerous because a lot of the times children hide it - so parents don't know."
Within ten months, Sewell, 14, was dead. He had taken his own life.
It was only then Ms Garcia and her family discovered a huge cache of messages between Sewell and a chatbot based on Game of Thrones character Daenerys Targaryen.
