  Once again, we set things up so that if there are no forces on the bar, it will be completely absorbed at L+. But we now postulate that if the bar should hit the point P, it will fracture: part of it (the part that hits L+) will be sent back in time and the rest will continue on above L+. So continuity of a sort is restored: now we have not just the possibility of the whole charge being sent back or nothing, we have the continuum degrees of charge in between.