[The night has many faces: When schistocytes step out of line].

We present a case study of a patient with paroxysmal nocturnal haemoglobinuria (PNH) which first presented clinically as a haemolytic crisis, potentially triggered by a SARS-CoV-2 infection. This case highlights the diagnostic challenges involved in distinguishing between PNH and thrombotic microangiopathy (TMA), particularly in emergency situations. Administering eculizumab early on, as it is effective in treating both diseases, was crucial in stabilising the patient before a definitive diagnosis could be confirmed.