Does there exist a purely quantum mechanical carrier of the imprints of gravitation? The motivation for considering this question arises from the following historical scenario: Suppose a time traveller from today visited Einstein in 1907, when he had the ``happiest thought of his life'', just in time before Einstein actually started on the path which led towards his formulation of gravitation (general relativity). Suppose that this time traveller told Einstein about relativistic quantum mechanics, about event horizons, and about Rindler's exact spacetime coordinatization of paired accelerated frames. Would that visitor from today have been able to influence the final form of the subsequent theory of gravitation? Put differently, how different would the course of history have been if Einstein had grafted relativistic quantum mechanics and Rindler spacetime onto the roots of gravitation instead of its trunk or branches?