  The low-lying Dirac modes become localised at the finite-temperature
transition in QCD and in other gauge theories, suggesting a general connection
between their localisation and deconfinement. The simplest model where this
connection can be tested is $\mathbb{Z}_2$ gauge theory in 2+1 dimensions. We
show that in this model the low modes in the staggered Dirac spectrum are
delocalised in the confined phase and become localised in the deconfined phase.
We also show that localised modes correlate with disorder in the Polyakov loop
configuration, in agreement with the "sea/island" picture of localisation, and
with negative plaquettes. These results further support the conjecture that
localisation and deconfinement are closely related.
