An Improbable Move

Jacques Mieses was a competent, though somewhat uneven chess player - but he did have his moments.   Arturo Reggio was a five time Italian champion, but probably the weakest player in Monte Carlo 1903 ( excepting the inscrutable Col. Moreau ).  Here is Mieses' improbable move - 22. . . Rg3 - and its possible variations, followed by the full game in which Reggio found the best continuation - though it, too, proved inadequate: