  In this paper we consider the motion of a rotating black hole through a
static, homogeneous, massless scalar field. In the general case, a constant
vector of the field gradient can be timelike, spacelike or null. We consider
and compare all of these cases. We demonstrate that as a result of the
interaction of the black hole with the scalar field, its mass, spin and
relative velocity with respect to the field can change. We obtain the equations
describing the evolution of these parameters and present solutions of the
obtained equations for some simple cases.
