  We study the massless flow from the critical point (dilute loops) to the
low-temperature phase (dense loops) of the O(n) loop gas model when the model
is coupled to 2D gravity. The flow is generated by the gravitationally dressed
thermal operator \Phi_{1,3} coupled to the renormalized loop tension \lambda ~
T-T_c. We find that the susceptibility as a function of the thermal coupling
\lambda and the cosmological constant \mu satisfies a simple transcendental
equation.
