We calculate the next-to-next-to-leading correction to the expectation value
of the Polyakov loop or equivalently to the free energy of a static charge.
This correction is of order g5. We show that up to this order the free
energy of the static charge is proportional to the quadratic Casimir operator
of the corresponding representation. We also compare our perturbative result
with the most recent lattice results in SU(3) gauge theory.Comment: 65 pages, 13 figure