  We show that the charge and thermal transport measurements on ultraclean
crystals of URu2Si2 reveal a number of unprecedented superconducting
properties. The uniqueness is best highlighted by the peculiar field dependence
of thermal conductivity including the first order transition at Hc2 with a
reduction of entropy flow. This is a consequence of multi-band
superconductivity with compensated electronic structure in the hidden order
state of this system. We provide strong evidence for a new type of
unconventional superconductivity with two distinct gaps having different nodal
topology.
