  Low-altitude twisted magnetic fields may be relevant to atmospheric heating
in the quiet Sun, but the exact role, topology, and formation of these twisted
fields remains to be studied. We investigate the formation and evolution of a
preflare flux rope in a stratified, 3D MHD simulation. One puzzle is that this
modelled flux rope does not form by the usual mechanisms at work in larger
flares such as flux emergence, flux cancellation, or tether-cutting. Using
Lagrangian markers to trace representative field lines, we follow the
spatiotemporal evolution of the flux rope. We isolate flux bundles associated
with reconnecting field line pairs by focusing on thin current sheets within
the flux system. We also analyze the time-varying distribution of the
force-free parameter as the rope relaxes. Lastly, we compare different seeding
methods for magnetic fields and discuss their relevance. We show that the
modeled flux rope is gradually built from coalescing, current-carrying flux
tubes. This occurs through a series of component reconnections that are driven
by flows in the underlying convection zone. These reconnections lead to an
inverse cascade of helicity from small to larger scales. We also find that the
system attempts to relax toward a linear force-free field, but that the
convective drivers and eventual nanoflare prevent full relaxation. Using a
self-consistently driven simulation of a nanoflare event, we show for the first
time an inverse helicity cascade tending toward a Taylor relaxation in the
Sun's corona, resulting in a well-ordered flux rope that later reconnects with
surrounding fields. This provides clues toward understanding the buildup of
nanoflare events in the quiet Sun through incomplete Taylor relaxations when no
flux emergence or cancellation is observed.
