Surprising and unexpected structure, some tough choices for the characters to make (you impressed me there, John), some impassioned line readings, and a climax I really did not see coming and that I watched wide-eyed.
I've wavered on my commitment to the show, which can be uneven...plus its dialogue is usually, um, less than natural, and not in an interesting stylized way either. (And a marketing thing: this season's early episodes were advertised with those overly bright "super fan!" radio ads. Made the show sound wacky. WACKY IS WRONG HERE.) But episodes like tonight's, the one with the aircraft carrier, and a good chunk of the first season keep me committed. Keep it up, everyone involved.