Excellent one, thanks to Enigmatist! Several where I knew what it had to be but only after a while could I figure out the parsing, which is very satisfying. CsOD 6a, 9d, 24ac, 27ac, and 10ac.
I was flummoxed by 16d, both halves being unfamiliar. For American solvers I suggest trying the following (to avoid spoilers I have rotated it 13 letters, paste it into rot 13 dot com to see the clue):
Znetrel, n cbbe guvat gung nva'g jung fur hfrq gb or (4, 4) [Vg jvyy abg tvir cerpvfryl gur fnzr nafjre ohg vg jvyy svg]
I was going to say that I hadn't parsed 21ac but I just figured it out. Still not totally sure about 14ac, is there a 2, 2 involved? I typed in the correct answer at one point, hit the check button, and was stunned to see it disappear completely. Then after getting some crossers I realized that it's Saturday and there is no check button, I had hit "clear."