Kepler-413 is an orange K-type dwarf (about 0.82 solar masses, 4,700 K, 0.78 solar radii), 848 light-years from Earth. Kepler-413 b is a circumbinary planet whose transits switch on and off for years because its orbit precesses rapidly. Kepler-413 b is a 0.21-Jupiter-mass companion, with an orbital period of 66.3 days, at 0.355 AU from its star, on an eccentric orbit (e ≈ 0.12), discovered in 2014 via transit. The planet was found when it crossed the face of its star, producing periodic dips in brightness that reveal its size and orbital period to space-based photometry. The planet's marked eccentricity suggests past scattering events or perturbations from unseen companions.