  We consider pseudo-classical knots in the non-orientable thickening of a
non-orientable surface, i.e., knots which are orientation-preserving paths in a
non-orientable $3$-manifold of the form (a non-orientable surface) $\times $
$[0,1]$. For this kind of knots we propose an analog of the Kauffman bracket
polynomial. The construction of the polynomial is very close to its classical
prototype, the difference consists in the using a new definition of the sign of
a crossing and a new definition of positive/negative smoothings of a crossing.
We prove that the polynomial is an isotopy invariant of pseudo classical knots
and show that the invariant is not a consequence of the classical Kauffman
bracket polynomial for knots in thickened orientable surface which is the
orientable double cover of the non-orientable surface under consideration.
