  We zoom in on the microscopic dynamics for fermions and quantum gravity
within the asymptotic-safety paradigm. A key finding of our study is the
unavoidable presence of a nonminimal derivative coupling between the curvature
and fermion fields in the ultraviolet. Its backreaction on the properties of
the Reuter fixed point remains small for finite fermion numbers within a
bounded range. This constitutes a nontrivial test of the asymptotic-safety
scenario for gravity and fermionic matter, additionally supplemented by our
studies of the momentum-dependent vertex flow which indicate the subleading
nature of higher-derivative couplings. Moreover our study provides further
indications that the critical surface of the Reuter fixed point has a low
dimensionality even in the presence of matter.
