  The mirror mode evolving in collisionless magnetised high-temperature
thermally anisotropic plasmas is shown to develop an interesting macro-state.
Starting as a classical zero frequency ion fluid instability it saturates
quasi-linearly at very low magnetic level, while forming elongated magnetic
bubbles which trap the electron component to perform an adiabatic bounce motion
along the magnetic field. {Further evolution of the mirror mode towards a
stationary state is determined by the bouncing trapped electrons which interact
with the thermal level of ion sound waves, generate attractive wake potentials
which give rise to formation of electron pairs in the lowest-energy singlet
state of two combined electrons. Pairing takes preferentially place near the
bounce-mirror points where the pairs become spatially locked with all their
energy in the gyration. The resulting large anisotropy of pairs enters the
mirror growth rate in the quasi-linearly stable mirror mode. It breaks the
quasilinear stability and causes further growth. Pressure balance is either
restored by dissipation of the pairs and their anisotropy or inflow of plasma
from the environment. In the first case new pairs will continuously form until
equilibrium is reached. In the final state the fraction of pairs can be
estimated. This process is open to experimental verification. To our knowledge
it is the only process where in high temperature plasma pairing may occur and
has an important observable macroscopic effect: breaking the quasilinear limit
and generation of localised diamagnetism.}
