  I study the very recently discovered S=-2 resonance Xi--(1886) by the NA49
collaboration at the CERN SPS. This resonance was already predicted, with a
mass close to 1.9 GeV, in a recent publication mostly dedicated to the S=1
resonance Theta+(1540). To confirm this recent prediction, I apply the same
standard quark model with a quark-antiquark annihilation constrained by chiral
symmetry. This method also explained with success the repulsive hard core of
nucleon-nucleon, kaon-nucleon exotic scattering, and the short range attraction
present in pion-nucleon and pion-pion non-exotic scattering. I find that
repulsion excludes the Xi-- as a dd ss u/bar s-wave pentaquark. I explore the
Xi-- as a heptaquark, equivalent to a N+K+K linear molecule, with positive
parity and total isospin I=3/2. I find that the kaon-kaon repulsion is
cancelled by the attraction existing in the kaon-nucleon channels. In our
framework this state is easier to bind than the Theta+ described by a pi+K+N
borromean bound-state. The remaining I=1/2 doublet and I=1 triplet of the
exotic anti-decuplet are also studied, and the coupling to p-wave decay
channels is briefly addressed.
