  We explore whether the axion which solves the strong CP problem can naturally
be much lighter than the canonical QCD axion. The $Z_\mathcal{N}$ symmetry
proposed by Hook, with $\mathcal{N}$ mirror and degenerate worlds coexisting in
Nature and linked by the axion field, is considered and the associated
phenomenology is studied in detail. On a second step, we show that dark matter
can be accounted for by this extremely light axion. This includes the first
proposal of a "fuzzy dark matter" QCD axion. A novel misalignment mechanism
occurs -- trapped misalignment -- due to the peculiar temperature dependence of
the $Z_\mathcal{N}$ axion potential, which in some cases can also dynamically
source the recently proposed kinetic misalignment mechanism. The resulting
universal enhancement of all axion interactions relative to those of the
canonical QCD axion has a strong impact on the prospects of ALP experiments
such as ALPS II, IAXO and many others. For instance, even Phase I of Casper
Electric could discover this axion.
