At this point I'd pip the chick. Locate the beak and carefully tear a small peice of membrane away with a pair of tweezers. Like stated earlier this will signal the chick to draw in the blood and yolk sac. At 24 days the chick will be quickly depleted of nutrients and will be much weaker. Keep the membrane moist and an hour or two after pipping see if you can't get some more membrane away from the chick without it bleeding. Stop if it bleeds and continue in another hour. Repeat this until the chick is out. I would bet money on it that this chick won't hatch itself out and needs assistance if it has a chance to survive.
I had a similar situation years ago. A broody of mine was sitting on some eggs and there was this horrible smell. I suspected a rotten egg exploded so I lifted the broody up and yep, sure enough, there was a horrific mess. So I cleaned her up, cleaned up the nest, and since it was day 24 or 25 in the middle of a really hot summer I decided to get rid of all the eggs. I figured they had gone bad and since they were contaminated wouldn't hatch anyways. It was mid morning so I didn't candle them, I just listened for peeping and cracked opened the fat end and peeked inside to make sure there wasn't a chick. When I got to the last egg I opened the large end and the thing started bleeding. I couldn't believe one of the eggs was still alive and I was in shock! I was maybe 14 or 15 at the time, no incubator, no car, the dumb broody was off the nest and freaking out, and I lived miles away from any civilization. So I brought the egg inside with me and decided I'd do what I could to help it. I brought it inside, cradeled it in my hands and kept it warm. It looked a lot like yours does now, except I worried about how it would breathe so after a few hours I located its beak and broke a small hole. I noticed the membrane didn't bleed when I did this so I tore a little off around the edges. It started to bleed again so I moistened the drying membrane with warm water, waited another hour or so and tore a little more off until I seen more blood. I stopped, waited, and repeated until I had the little chick out. It took ALL DAY. Good thing I was a kid without a job or something, and I didn't have school! I would've had to call in sick or play hookie. The chick ended up living and of course turned out to be a rooster. Helping a chick isn't always a bad thing if a person has patience and the chick is developed enough to breathe oxygen. Going slow and having patience is the key!
Good luck.
