  We clarify the relationship between probe analysis of the supergravity dual
and the large-N solution of the localization matrix model for the planar N = 2*
super-Yang-Mills theory. A formalism inspired by supergravity allows us to
systematically solve the matrix model at strong coupling. Quite surprisingly,
we find that quantum phase transitions, known to occur in the N = 2* theory,
start to be visible at the third order of the strong-coupling expansion and
thus constitute a perturbative phenomenon on the string worldsheet.
