An 1882 stage classic that the New York Times, in 2018, called “suddenly as timely as a tweet,” Henrik Ibsen's An Enemy of the People will be presented, in a modern-day re-imaging, at Davenport venue the Mockingbird of Main September 30 through October 9, its exploration of the impacts of pollution and moral complacency perhaps even more relevant now than it was in the 19th century.