  Context: Optical nova lightcurves often have structures, such as rapid
declines and recoveries, due to nebular or dusty phases of the ejecta. Nova
Cygni 2006 (V2362 Cyg) underwent an unusual brightening after an early rapid
decline. The shape of the lightcurve can be compared to that of V1493 Aql, but
the whole event in that case was not as bright and only lasted a couple of
weeks. V2362 Cyg had a moderately fast decline of t_2 = 9.0 before
rebrightening, which lasted 250 days after maximum. Aims: We present an
analysis of our own spectroscopic investigations in combination with AAVSO
photometric data covering the whole rebrightening phase until the return to the
final decline. Methods: We used the medium resolution spectroscopy obtained in
ten nights over a period of 79 nights to investigate the change of the velocity
structure of the ejecta. The publicly available AAVSO photometry was used to
analyze the overall properties and the energy of the brightening. Results:
Although the behavior of the main outburst (velocity, outburst magnitude, and
decline timescales) resembles a ``normal'' classical nova, the shell clearly
underwent a second fast mass ejecting phase, causing the unusual properties.
The integrated flux during this event contributes ~ 40 % to the total radiation
energy of the outburst. The evolution of the H_alpha profile during the bump
event is obtained by subtracting the emission of the detached shells of the
main eruption by a simple optically thin model. A distance of D ~ 7.5
{+3.0}{-2.5} kpc and an interstellar extinction E(B-V) = 0.6 +/- 0.1 was also
derived.
