[en] There is accumulating evidence for a difference between neutrino and antineutrino oscillations at the ∼1 eV² scale. The MiniBooNE experiment observes an unexplained excess of electron-like events at low energies in neutrino mode, which may be due, for example, to either a neutral current radiative interaction, sterile neutrino decay, or to neutrino oscillations involving sterile neutrinos and which may be related to the LSND signal. No excess of electron-like events (-0.5 ± 7.8 ± 8.7), however, is observed so far at low energies in antineutrino mode. Furthermore, global 3+1 and 3+2 sterile neutrino fits to the world neutrino and antineutrino data suggest a difference between neutrinos and antineutrinos with significant (sin² 2θ_μμ ∼ 35%) (bar ν)_μ disappearance. In order to test whether the low-energy excess is due to neutrino oscillations and whether there is a difference between ν_μ and (bar ν)_μ disappearance, we propose building a second MiniBooNE detector at (or moving the existing MiniBooNE detector to) a distance of ∼200 m from the Booster Neutrino Beam (BNB) production target. With identical detectors at different distances, most of the systematic errors will cancel when taking a ratio of events in the two detectors, as the neutrino flux varies as 1/r² to a calculable approximation. This will allow sensitive tests of oscillations for both ν_e and (bar ν) appearance and ν_μ and (bar ν)_μ disappearance. Furthermore, a comparison between oscillations in neutrino mode and antineutrino mode will allow a sensitive search for CP and CPT violation in the lepton sector at short baseline (Δm² > 0.1 eV²). Finally, by comparing the rates for a neutral current (NC) reaction, such as NC π⁰ scattering or NC elastic scattering, a direct search for sterile neutrinos will be made. The initial amount of running time requested for the near detector will be a total of ∼2E20 POT divided between neutrino mode and antineutrino mode, which will provide statistics comparable to what has already been collected in the far detector. A thorough understanding of this short-baseline physics will be of great importance to future long-baseline oscillation experiments.