We report on the first high frequency VLBI observations of the nearby broad absorption line quasar ( BALQSO ) , Mrk 231 . Three epochs of observations were achieved at 15 GHz and 22 GHz , two of these included 43 GHz observations as well . The nuclear radio source is resolved as a compact double . The core component experienced a strong flare in which the flux density at 22 GHz increased by > 150 \% ( 45 mJy ) in three months . Theoretical models of the flare imply that the emission is likely enhanced by very strong Doppler boosting of a highly relativistic ejecta with a kinetic energy flux , Q \sim 3 \times 10 ^ { 43 } \mathrm { ergs / sec } . Combining our data with two previous epochs of 15 GHz data , shows marginal evidence for the slow advance of the secondary component ( located \approx 0.97 pc from the core ) over a 9.4 year span . We estimate that the long term time averaged kinetic energy flux of the secondary at \overline { Q } \approx 10 ^ { 42 } \mathrm { ergs / sec } . Low frequency VLBA observations indicate that the secondary is seen through a shroud of free-free absorbing gas with an emission measure of \approx 10 ^ { 8 } \mathrm { cm } ^ { -6 } \mathrm { pc } . The steep spectrum secondary component appears to be a compact radio lobe that is associated with a working surface between the ram-pressure confined jet , and a dense medium that is likely to be the source of the free-free absorption . The properties of the dense gas are consistent with the temperatures , displacement from the nucleus and the column density of total hydrogen commonly associated with the BAL wind .