question: Background: Prosthetic valve dehiscence is a manifestation of endocarditis which may be difficult to diagnose based on imaging. Case: A 68-year-old female with mechanical mitral valve replacement (MVR) complicated by recurrent endocarditis requiring two redo MVR presented with subacute chills, nausea, fatigue and dyspnea. Evaluation revealed leukocytosis, elevated NT-proBNP, acute kidney injury, negative blood cultures, and negative SARS-CoV2. Transthoracic echocardiography (TTE) showed normal prosthetic valve function. She was managed for acute decompensated heart failure and placed on empiric antibiotics. She continued to have chills, night sweats and developed hypotension. Blood cultures remained negative, and no source of infection was identified on imaging. Decision-making: To aid in differentiation shock, patient underwent right heart catheterization. This revealed severe cardiogenic shock, with cardiac index of 1.3 L/min/m2. Repeat TTE demonstrated dehiscence of the prosthetic mitral valve, which was confirmed on transesophageal echocardiogram (Figure 1). An intra-aortic balloon pump was placed, and inotropic support provided. Patient underwent successful redo MVR using a bioprosthetic valve. Tissue microbiology was positive for coagulase negative staph. Conclusion: Unmasking the etiology of vague clinical presentations may pose a challenge. Our case highlights the importance of a high index of suspicion and serial imaging when patients present with B-type symptoms. [Formula presented]