Paloma Shemirani was just 23 when she died from cancer in 2024. She had rejected chemotherapy in favour of alternative treatments. Her brothers say that decision was influenced by their mother Kate Shemirani, a vocal British conspiracy theorist who shares misinformation about cancer. She disputes their account. So what really happened? Through testimony from family, friends and experts, Marianna Spring investigates Paloma's case and the rise of health conspiracy theories on social media following the pandemic. Are social media companies’ algorithms pushing potentially harmful content at vulnerable patients – and are anti-medicine ideas going mainstream?