  We consider the realization of four-dimensional theories with N = 2
supersymmetry as M-theory configurations including a five-brane. Our emphasis
is on the spectrum of massive states, that are realized as two-branes ending on
the five-brane. We start with a determination of the supersymmetries that are
left unbroken by the background metric and five-brane. We then show how the
central charge of the N = 2 algebra arises from the central charge associated
with the M-theory two-brane. This determines the condition for a two-brane
configuration to be BPS-saturated in the four-dimensional sense. By imposing
certain conditions on the moduli, we can give concrete examples of such
two-branes. This leads us to conjecture that vectormultiplet and hypermultiplet
BPS-saturated states correspond to two-branes with the topology of a cylinder
and a disc respectively. We also discuss the phenomenon of marginal stability
of BPS-saturated states.
