  We study the evolution of a small-scale emerging flux region (EFR) in the
quiet Sun, from its emergence to its decay. We track processes and phenomena
across all atmospheric layers, explore their interrelations and compare our
findings with recent numerical modelling studies. We used imaging, spectral and
spectropolarimetric observations from space-borne and ground-based instruments.
The EFR appears next to the chromospheric network and shows all characteristics
predicted by numerical simulations. The total magnetic flux of the EFR exhibits
distinct evolutionary phases, namely an initial subtle increase, a fast
increase and expansion of the region area, a more gradual increase, and a slow
decay. During the initial stages, bright points coalesce, forming clusters of
positive- and negative-polarity in a largely bipolar configuration. During the
fast expansion, flux tubes make their way to the chromosphere, producing
pressure-driven absorption fronts, visible as blueshifted chromospheric
features. The connectivity of the quiet-Sun network gradually changes and part
of the existing network forms new connections with the EFR. A few minutes after
the bipole has reached its maximum magnetic flux, it brightens in soft X-rays
forming a coronal bright point, exhibiting episodic brightenings on top of a
long smooth increase. These coronal brightenings are also associated with
surge-like chromospheric features, which can be attributed to reconnection with
adjacent small-scale magnetic fields and the ambient magnetic field. The
emergence of magnetic flux even at the smallest scales can be the driver of a
series of energetic phenomena visible at various atmospheric heights and
temperature regimes. Multi-wavelength observations reveal a wealth of
mechanisms which produce diverse observable effects during the different
evolutionary stages of these small-scale structures.
