The Canarias InfraRed Camera Experiment (CIRCE) for the Gran Telescopio Canarias (GTC) is one of the few infrared instruments in the world using a four-beam polarimeter. The classical double-beam configuration consists of a half-wave plate (HWP) and a Wollaston Prism (WP) that allow measurement of two linear polarization components of the light in a single exposure. Instead, our instrument includes a WeDoWo - a dual-WP system with principal axis at 45 degrees that is inserted near the pupil plane. Thus, all linear Stokes parameters can be obtained in a single observation. We can also perform medium-resolution (R=400-1500) spectro-polarimetry by inserting a grism in the beam. The CIRCE focal plane mask includes three field stops for imaging polarimetry, three slits for spectropolarimetry and three slits for regular spectroscopy of nearby sources. CIRCE also has a high-speed photometry mode that, combined with polarimetry on a large telescope such as the GTC, will provide important insights into highly-variable sources such as microquasars.