  Chiral representations are the key in obtaining light fermions from some
ultra-violet completed theories. The well-known chiral example is one family
set of fifteen chiral fields in the standard model. We find a new chiral theory
SU(2)$_{\rm dark}\times$U(1)$_Q$ with sixteen chiral fields, which does not
have any gauge and gravitational anomalies. The group SU(2)$_{\rm
dark}\times$U(1)$_Q$ may belong to the dark sector, and we present a derivation
of the spectrum from the E$_8\times$E$_8'$ hetrotic string. Necessarily, there
appear two degrees at low energy: two dark Z's, or a dark Z plus a dark-photon.
Being chiral, there is a chance to probe this theory at TeV accelerators. Since
the model belongs to the dark sector, the way to probe it is through the
kinetic mixing.
