  We argue that near a Kondo breakdown critical point, a spin liquid with
spatial modulations can form. Unlike its uniform counterpart, we find that this
occurs via a second order phase transition. The amount of entropy quenched when
ordering is of the same magnitude as for an antiferromagnet. Moreover, the two
states are competitive, and at low temperatures are separated by a first order
phase transition. The modulated spin liquid we find breaks $Z_4$ symmetry, as
recently seen in the hidden order phase of URu$_2$Si$_2$. Based on this, we
suggest that the modulated spin liquid is a viable candidate for this unique
phase of matter.
