The latest article about Atlas Shrugged Part 2 in Reason magazine offers this, about the new actress playing Dagny Taggart:
Part IIs new Dagny Taggart—the railroad magnate heroine struggling to keep the motors of the world running while mysterious forces try to shut them down—is Samantha Mathis (perhaps most famously of Pump Up the Volume opposite Christian Slater). She wasn’t on set Wednesday, but co-screenwriter Duncan Scott, fresh to this project but with a long history with Ayn Rand and the movies, showed me some rough footage he shot of her filming a couple of scenes on earlier days. One of them quietly helps frame the deteriorating world of Atlas—with Mathis walking past grim lines of citizens selling their possessions on the streets in a world of 20 percent unemployment and $40 per gallon gas, shot outside the Los Angeles convention center. Another was of her fateful solo plane ride. Kaslow and Scott are both excited about their new Dagny. Scott says Mathis is always believable as a woman serious and powerful enough to run a railroad, and Kaslow says she’s fully embraced the character and went out of her way to read the novel to understand the character more fully.

