Reconstructed power spectra with the base ΛCDM best fit subtracted. The mean spectra shown are for the floating r and the two fixed r cases with 12 cubic spline knots. These should be contrasted with the running best-fit mean (green) and the similar looking uniform n_s case in which τ has been lowered from its best-fit base ΛCDM value to 0.04. Data points are the Planck 2015 Commander (ℓ< 30) and Plik (ℓ ≥ 30) temperature power spectrum.