  We show how to incorporate massive spinning fields into the Euclidean path
integral of three-dimensional quantum gravity via its Chern-Simons formulation.
The coupling of the spinning fields to gravity is captured by a Wilson spool, a
collection of Wilson loops winding around closed paths of the geometry, and
generalizes the proposal of [1,2]. We present a robust derivation of the Wilson
spool by providing a new group-theoretic perspective of the quasinormal mode
method for one-loop determinants. We test our proposal on Euclidean BTZ and
$S^3$ backgrounds. We also evaluate explicitly the quantum corrections to the
path integral on $S^3$, and report on how $G_N$ and the mass are renormalized
to leading order in perturbation theory.
