In real life, POCUS is always integrated into the complete patient evaluation alongside the clinical history and physical examination. The intensivist who performs POCUS does not do so in a vacuum. All aspects of the patient’s case are known before the POCUS, allowing the intensivist to ask and answer specific questions about the patient. Why is my patient hypotensive? Goal-directed echocardiography may answer this question. Goal-directed echocardiography categorizes the shock state accurately and immediately, allowing potentially life-saving therapeutics to be given (eg, thrombolysis in massive pulmonary embolus, pericardiocentesis in tamponade). Why is my patient in hypoxemic respiratory failure? Does he or she have a pneumothorax? A massive pleural effusion or pneumonia? In this way, the intensivist uses a whole body ultrasound approach to help answer an ICU daily question: Why is my patient critically ill? The Ultrasound Corner cases illustrate how POCUS adds to daily patient evaluation and challenges readers to test their level of competence in interpreting the video images. The cases demonstrate how to use POCUS in all aspects of critical care from the diagnosis and management of shock and respiratory failure to the help with procedural guidance such as chest tube placement and pericardiocentesis. Less common applications of ultrasound are also explored, such evaluating optic nerve diameter for identification of increased intracranial pressure. However, make no mistake: becoming competent in critical care ultrasound requires hands-on training, starting with being trained by someone experienced in POCUS, whether at a course or personalized mentoring, and continuing with individual, at the bedside, “on-the-job training.” But as a trusty companion, Ultrasound Corner will provide the learner with reassurance in image interpretation and clinical integration with high-quality cases and just may make some of you authors. We encourage all who perform POCUS to submit both “the bread and butter” critical care cases, such as left and right ventricular failure cases, commonly encountered in daily ICU practice, and cases where POCUS allowed a timely diagnosis of less common disease processes. We have recently received submissions that outline POCUS for intracerebral hypertension, septic pulmonary emboli, pyopneumothorax, and diaphragmatic dysfunction. These cases highlight the remarkable creativity that physicians possess when faced with a critically ill patient and no diagnosis. They say necessity is the mother of invention; therefore, we look forward to reviewing all your ultrasound cases.