As far as I know, a black hole is a singularity in the space-time. The space-time becomes so curved that the geodesics can't get out, i.e., the gravitational field becomes so strong that information can not get out. OK! But what about gravitational waves? As far as I know, gravitational waves are perturbations in the space-time and hence I suppose that they can climb the space-time curvature of the black hole. I believe that this must be wrong since otherwise the black hole would emit information from inside of the event horizon which I never heard of. So thinking about this I have come across with some questions. Do the gravitational waves also follow a geodesic in space-time? How can one define a geodesic for the motion of a perturbation of the space-time along this very same space-time? Do the trajectory of a gravitational wave also bend due to the presence of a gravitational field? Thanks for any answer.