Director Lynn Shelton (Humpday), propelled by a desire to work again with comedian Marc Maron, here delivers a deftly economical comedy that succeeds where one might think it shouldn’t. Maron stars as a pawn shop owner in Birmingham, Alabama, who gets roped into helping a lesbian couple sell a Civil War sword that’s alleged to prove the south really won the thing. Their buyer? An extremist right-wing outfit committed to advancing that alternate view of history. It sounds nutty—and it is—but Shelton, who cowrote the script with Mike O’Brien, and the cast (which includes Michaela Watkins and Jillian Bell as the couple, plus Jon Bass and Dan Bakkedahl) execute the provocative scenario with amiable persiflage. It’s equal parts spry, improvisational comedy and salient social commentary; much like the post-Mutual Appreciation films of Shelton’s colleague Andrew Bujalski, this is a prime example of what can happen when mumblecore filmmakers continue to cultivate their skills.