We present a model in which the 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 \approx - 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 .