  The new ekpyrotic scenario attempts to solve the singularity problem by
involving violation of the null energy condition in a model which combines the
ekpyrotic/cyclic scenario with the ghost condensate theory and the curvaton
mechanism of production of adiabatic perturbations of metric. The Lagrangian of
this theory, as well as of the ghost condensate model, contains a term with
higher derivatives, which was added to the theory to stabilize its vacuum
state. We found that this term may affect the dynamics of the cosmological
evolution. Moreover, after a proper quantization, this term results in the
existence of a new ghost field with negative energy, which leads to a
catastrophic vacuum instability. We explain why one cannot treat this dangerous
term as a correction valid only at small energies and momenta below some UV
cut-off, and demonstrate the problems arising when one attempts to construct a
UV completion of this theory.
