Katie Wood was a fit, fast-moving Londoner until the mould in her refurbished flat quietly poisoned her, weakening her immune system so badly she caught Legionnaires' disease and was rushed to hospital. Misdiagnosed and told it was "all in her head", she fought off the infection with no treatment, only to be left with Chronic Fatigue Syndrome. It took her brother's biohacking instincts and a health optimisation coach to uncover the real culprit: toxic mould poisoning from her own home. Today she shares her story to expose the hidden danger sitting in millions of homes.