Mucormycosis, or the black fungus, is a very rare but serious infection caused by a group of molds called mucormycetes. These molds live throughout the environment. It affects the sinuses, the brain and the lungs and can be life-threatening in diabetic or severely immunocompromised individuals. During a deadly and difficult COVID-19 second wave in India, doctors are now reporting more and more cases involving this infection among recovering and recovered Covid-19 patients. Prof. Natarajan warns against this dangerous infection and gives advice to his colleagues and patients in India, to better protect and recognise it during this harsh pandemic times.