A routine chest X-ray in a 78-year-old female patient suggested a retained vascular catheter in the right ventricle (RV). On transthoracic echocardiography, a prominent linear echo was found in the RV and the patient was referred for cardiac computed tomography and magnetic resonance imaging. Although neither of these tests showed evidence of a retained foreign body in the RV, they could not clarify the nature of the linear structure within the RV cavity. Finally, transesophageal echocardiography, using a matrix array three-dimensional probe solved the mystery: the linear structure in question within the RV was a large papillary muscle with attachments to the anterior leaflet of the tricuspid valve and an unusual origin from the interventricular septum.