  The standard field-theoretical procedure to study the effect of long
wavelength fluctuations on a genuine second-order phase transition is applied
to the Mode-Coupling-Theory (MCT) dynamical singularity at $T_c$ in the $\beta$
regime. Technically this is achieved by a dynamical field-theoretical
decoration of MCT that can be studied by a loop expansion. An explicit
computation shows that at all orders the leading contributions are the same of
a dynamical stochastic glassy equation, {\it i.e} an extension of the standard
MCT equation for the critical correlator with local random fluctuations of the
separation parameter. It is suggested that the equation is an essential
ingredient in the process that turns the singularity at $T_c$ into a dynamical
crossover to activated dynamics.
