Beantown scribe Ronan Noone is getting a double play at Huntington Theater Company.Film and legit thesp Campbell Scott stars in Noone’s one-hander “The Atheist,” which will play a limited non-subscription run at the theater’s Stanford Calderwood Pavilion Sept. 12-30. The play, which was also produced last year off-B’way (starring Chris Pine) and in London this year (with Ben Porter), will be staged by artistic associate Justin Waldman. Work centers on unscrupulous journalist who finds himself in the middle of a scandal. Irish-born Noone’s latest, “Brendan” will preem in October at the Huntington. Scribe’s previous plays include “The Lepers of Baile Baiste” and “The Blowin of Baile Gall,” which had its Off Broadway debut — produced by Gabriel Byrne — at the Irish Arts Center in 2005.