  The energy densities achieved during central collisions of large nuclei at
the AGS may be high enough to allow the formation of quark--gluon plasma. We
propose that most collisions at AGS energies produce superheated hadronic
matter, but in rare events a droplet of quark--gluon plasma is nucleated. We
estimate the probability of this to occur based on homogeneous and
inhomogeneous nucleation theory and discuss possible experimental signals.
