  Accretion is the prime mode of star formation, but the exact mode has not yet
been identified in the Herbig Ae/Be mass range. We provide evidence that the
the maximum variation in mass-accretion rate is reached on a rotational
timescale, which suggests that rotational modulation is the key to
understanding mass accretion. We show how spectropolarimetry is uniquely
capable of resolving the innermost (within 0.1 AU) regions between the star and
the disk, allowing us to map the 3D geometry of the accreting gas, and test
theories of angular momentum evolution. We present Monte Carlo line-emission
simulations showing how one would observe changes in the polarisation
properties on rotational timescales, as accretion columns come and go into our
line of sight.
