If they were rotten then that's why your hen gave up on them. Hens can tell if eggs are good or not.Well, the cold must have done them in. That one egg may have been alive but it was probably too weak to get out of that shell. I gave up on them tonight and cracked them open just out of morbid curiosity I guess. They were all rotten. Just gonna have to try again, and don't count your chickens before they hatch!