 Video versions of this feature (using the title City Of Lost Men) hav the  last reel of the serials final chapter cut in after the feature proper fades  out, showing the destruction of the main villains but not explaining how all  the principals suddenly get from the trading post back into the underground  lost city.  Its not clear who is responsible for this amendment, although  main titles suggest it may have been done for a 1970s reissue.