  Despite its seemingly simple composition and structure, the pairing mechanism
of FeSe remains an open problem due to several striking phenomena. Among them
are nematic order without magnetic order, nodeless gap and unusual inelastic
neutron spectra with a broad continuum, and gap anisotropy consistent with
orbital selection of unknown origin. Here we propose a microscopic description
of a nematic quantum spin liquid that reproduces key features of neutron
spectra. We then study how the spin fluctuations of the local moments lead to
pairing within a spin-fermion model. We find the resulting superconducting
order parameter to be nodeless $s\pm d$-wave within each domain. Further we
show that orbital dependent Hund's coupling can readily capture observed gap
anisotropy. Our prediction calls for inelastic neutron scattering in a
detwinned sample.
