Complex sentence: Sometimes, as with "The Shadow Over Innsmouth" (which included a rousing chase that supplied action) he never submitted a completed story; he work was circulated among friends one of whom unsuccesfully submitted on his own initiative.
Split into simpler sentences: Sometimes, as with "The Shadow Over Innsmouth" he never submitted the work, even though it included rousing chase that supplied action. The work was circulated among friends one of whom unsuccesfully submitted on his own initiative.