Consider this nifty package tour a kind of Monsters of Social-Justice Fiction. Every two years, the Bellwether Prize established by Barbara Kingsolver awards $25,000 to a novel that advances social justice themes and examines the effect of culture and politics on human relationships. Two Bellwether winners appear today at Parnassus Books for a joint reading and signing. Ironman triathlete, former seismologist/geophysicist and mentor to Afghan women writers Naomi Benaron won in 2010 for her novel Running the Rift, the story of a Rwandan boy who grows to find his gift for running a lifesaver in the grisly Hutu-Tutsi conflict. Brooklyn resident Hillary Jordan won in 2006 for Mudbound, a tale of postwar romance and racial conflict in 1946 Mississippi, which earned acclaim as one of the decade’s strongest debuts. She’s also the author of When She Woke, which updates The Scarlet Letter to a dystopian future where a woman literally stained red for her crimes defies a theocracy filled with perils. The joint appearance is free and open to the public.