The spectacular data delivered by NASA's Kepler mission not only boost the discoveries of planets orbiting other stars, but they also open a window on the inner workings of the stars themselves. Kepler has been a breakthrough for the study of RR Lyrae stars and the still mysterious Blazhko effect. I will present some of the most interesting results obtained so far.

To date, over 40 RR Lyrae stars have been found in the Kepler field. The outstandingly high-precision data of these stars are investigated within the RR Lyrae working group as part of the Kepler Asteroseismic Science Consortium (KASC).