I put 4 muscovy duck eggs and 2 cuckoo maran eggs in the incubator on 9/11. As of a few days ago there were 3 duck eggs and 1 chicken egg with veining. Yesterday when I candled, I noticed a very dense and largish looking mass inside the one duck egg that didn't have veining. It looked like what a candled egg would look like much further on, when an embryo stops developing....but obviously they aren't far enough along to have much development at this point. I left it in overnight because I'm a wimp and I'm scared of accidentally killing a live embryo. Today I got rid of the clear chicken egg and cracked open the weird duck egg. The whites are liquid to the point of being like water. The yolk looked like it was half hardboiled and half raw. What would cause this? I haven't had any temperature spikes or anything, and even if I did- why would only one egg be like this and not the rest? And why only half of the yolk cooked? It smelled bad too, though I'm guessing that's probably normal after being in the incubator for a week.