  We report a flare on the M9 dwarf DENIS 104814.7-395606.1, whose mass places
it directly at the hydrogen burning limit. The event was observed in a spectral
sequence during 1.3 hours. Line shifts to bluer wavelengths were detected in H
alpha, H beta, and in the Na D lines, indicating mass motions. In addition we
detect a flux enhancement on the blue side of the two Balmer lines in the last
spectrum of our series. We interpret this as rising gas cloud with a projected
velocity of about 100 km/s which may lead to mass ejection. The higher Balmer
lines H gamma to H 8 are not seen due to our instrumental setup, but in the
last spectrum there is strong evidence for H 9 being in emission.
