This story would have seemed to have fascinating potential, and still is compelling, but it seems like the spark couldn't generate a flame. It's about reincarnation, but we get there rather at random. I can see that possibly a back story might have been present at one time, but we have none in the film's present state.
A girl burglar robs a rich man's house. He catches her but seems incredibly forgiving, lets her go and just hands her his money. For his trouble, he's held up by her two male companions outside, but then, he just collapses. Why? Then for no apparent reason, she falls to a dead faint, too! What gives? The two are raced to a hospital, as the very real possibility of Sleeping Sickness was present a century ago. Nothing works. Now silly as it may seem, they decide to call in a Hindu mystic, famed for his hypnotic powers. He does his stuff and gets from the victims a story that in the murky past, in some weird India/Egypt/Babylon someplace, (going by the mishmash of costumes and art) the rich man in his earlier incarnation is on the slave market block, a prize because even then, he was a white man. He's bought by a wealthy guy with a turban and a palace, and a collection of wives. The big taboo is for a slave to get too chummy with said wives, but our hero falls for one of them, who's the ante-carnation of the little burglarette.
This all comes out and the two are sentenced to be killed and entombed together, and are. Then they snap out of it back 1914, the Hindu spilling the whole story, and everyone's happy to just let the couple hug in private, the last shot superimposes their long ago mummified bodies back in the tomb over their embrace.
This really should have been fleshed out a bit more. It would seem the random chance that in all time and space, these two carriers of long lost souls would come together then and there, all right. But what's with the strange paralyzing comas all of a sudden? Why was hypnotism the way out? In fact, just how would Hypnotism work? Who knows? It's just all spooky stuff that comes to miraculous aid in incomprehensible phantasy situations.
Noting the date of this film, surely the men who produced the 1932 film The Mummy could have seen it, and might've given a more serious thought to what would happen to ancient star-crossed lovers returning to the world in the Twentieth Century, and maybe not so seriously, in a lighter vein in Professor Beware (1938).