He's zipping! The first little spot you saw was the "pip" and now you get to witness the "zip". That little guy will keep turning in the egg and use his "eye tooth" to perforate the membrane and shell and then he will pop the top right off that egg and he will be so tired. After hatch, leave him in the bator probably overnight and he can go to the brooder by morning if he looks dry enough and active. He may not eat or drink for the first 24 hours or more and that is normal. Still, place food and water nearby. You should have your brooder area set up and ready. In all the excitement don't forget the brooder...lol. The membrane looks good with the paper towel there. I hope you don't have work tomorrow! You're not gonna be able to sleep much tonight.