We present optical and millimeter (continuum and molecular) observations of a cometary globule in the Trifid nebula showing clear signs of star formation activity. The globule is associated with a long jet finishing in a large bow shock. The HH jet can be seen in all the popular pictures of the Trifid. It has remained unrevealed although it has been in front of our eyes since the first high sensitivity photographic pictures of the Trifid. The jet emanates from the head of a cometary globule submitted to the strong UV field of the ionizing star of the Trifid. The continuum emission at 230 GHz follows the globule's head contour and consists of extended and weak emission plus a strong point source from where the jet seems to arise. High resolution spectroscopy in the SII line at 6730 A indicates that the jet is practically in the plane of the sky. The dust emission arises from a clump of ~= 5 M_odot. The molecular observations cover a larger surface and indicate a total mass for the globule of 30-50 M_odot.