A 58-year-old previously healthy woman was seen with sudden-onset headache radiating to the back at 7:40 pm. She arrived at the emergency department 20 minutes after symptom onset. The findings of the general examination and the neurological examination were unremarkable, except for mildly elevated blood pressure (158/82 mm Hg). A noncontrast head computed tomography (CT) scan was performed at 8:12 pm. It revealed a vague but homogeneous hyperdensity (40 Hounsfield units [H]) in the ventral midline of the midbrain, with the effacement of the interpeduncular cistern and ambient cistern (Figure, A). A diagnosis of spontaneous subarachnoid hemorrhage or spontaneous intracranial hypotension was initially considered by the radiologists. At 8:17 pm, a CT angiogram showed a linear enhancement in the ventral midline of the midbrain (Figure, B), but no aneurysm, dissection, or vascular malformation was seen. At 11:15 pm, the patient’s headache worsened, and she experienced slurred speech and a decreased level of consciousness. A second CT scan was completed at 11:20 pm, showing hyperdensity (65-70 H) in the ventral midline of the midbrain, interpeduncular cistern, and ambient cistern (Figure, C). The patient was diagnosed with midbrain hemorrhage extending into the brain cisterns. She received antifibrinolytic infusions with tranexamic acid, her blood pressure was controlled, and she was transferred to the neurointensive care unit. At 0:50 am the next day, her condition rapidly deteriorated, with deep coma (Glasgow Coma Scale score, 3) and respiratory depression. Subsequently, she underwent orotracheal intubation. At 1:50 am, the head CT scan was repeated, showing hematoma expansion (HE) in the midbrain hemorrhage with lateral ventricle hemorrhage and hydrocephalus (Figure, D). The patient’s guardian refused any surgical intervention. Eventually, she died of respiratory and cardiac failure 5 days after admission.