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Broad emission line outflows of active galactic nuclei have been proposed for many years but are very difficult to quantitatively study because of the coexistence of the gravitationally bound and outflow emission. We present detailed analysis of a heavily reddened quasar, SDSS J000610.67 | 121501.2, whose normal ultraviolet broad emission lines (BELs) are heavily suppressed by the dusty torus as a natural "coronagraph," and thus the blueshifted BELs (BBELs) can be reliably measured. The physical properties of the emission-line outflows are derived as follows: ionization parameter U similar to 10(-0.5), column density n(H) similar to 10(22.0) cm(-2), covering fraction of similar to 0.1, and upper limit density of nH similar to 10(5.8) cm(-3). The outflow gases are located at least 41 pc away from the central engine, which suggests that they have expanded to the scale of the dust torus or beyond. Besides, Ly alpha shows a narrow symmetric component, to our surprise, which is undetected in any other lines. After inspecting the narrow emission line region and the star-forming region as the origin of the Lya narrow line, we propose that the end result of outflows, diffusing gases in the larger region, acts as the screen of Lya photons. Future high spatial resolution spectrometry and/or spectropolarimetric observations are needed to make a final clarification.