  We present a model in which the equation of state parameter w approaches -1
near a particular value of z, and has significant negative values in a
restricted range of z. For example, one can have w ~ -1 near z = 1, and w >
-0.2 from z = 0 to z = 0.3, and for z > 9. The ingredients of the model are
neutral fermions (which may be neutrinos, neutralinos, etc) which are very
weakly coupled to a light scalar field. This model emphasises the importance of
the proposed studies of the properties of dark energy into the region z > 1.
