  The intermetallic compound Eu$_5$In$_2$Sb$_6$, an antiferromagnetic material
with nonsymmorphic crystalline structure, is investigated by magnetic,
electronic transport and specific heat measurements. Being a Zintl phase,
insulating behavior is expected. Our thermodynamic and magnetotransport
measurements along different crystallographic directions strongly indicate
polaron formation well above the magnetic ordering temperatures. Pronounced
anisotropies of the magnetic and transport properties even above the magnetic
ordering temperature are observed despite the Eu$^{2+}$ configuration which
testify to complex and competing magnetic interactions between these ions and
give rise to intricate phase diagrams discussed in detail. Our results provide
a comprehensive framework for further detailed study of this multifaceted
compound with possible nontrivial topology.
