  In this work the dynamic magnetic field within a tearing-unstable
three-dimensional (3D) current sheet about a magnetic null point is described
in detail. We focus on the evolution of the magnetic null points and flux ropes
that are formed during the tearing process. Generally, we find that both
magnetic structures are created prolifically within the layer and are
non-trivially related. We examine how nulls are created and annihilated during
bifurcation processes, and describe how they evolve within the current layer.
The type of null bifurcation first observed is associated with the formation of
pairs of flux ropes within the current layer. We also find that new nulls form
within these flux ropes, both following internal reconnection and as adjacent
flux ropes interact. The flux ropes exhibit a complex evolution, driven by a
combination of ideal kinking and their interaction with the outflow jets from
the main layer. The finite size of the unstable layer also allows us to
consider the wider effects of flux rope generation. We find that the unstable
current layer acts as a source of torsional MHD waves and dynamic braiding of
magnetic fields. The implications of these results to several areas of
heliophysics are discussed.
