With a OG over 1.060, it becomes harder and harder for the yeast to thrive in the wort. So given the fact that you underpitched combined with the high OG, I'd say that 1.024 is going to be about as low as it's going to get. I'd rack it to secondary and let it sit for another couple weeks just to age, but I wouldn't expect it to get much dryer.
"let me be the first to welcome our new insectile overlords"
On deck: Breakfast stout
Secondary: American Pale Ale
Kegged: Imperial red ale, Breakfast stout, Chipotle Irish red ale, Biermuncher's C3C cream ale