Egg under broody seems half dark and half air cell day 18?

[TS92]

Just did the egg autopsy and yes egg 4 must have quit at about day 10 or 11 I think and egg 3 had a fully formed chick inside must have Just not had the strength to hatch

 

[Alaskan]

Just did the egg autopsy and yes egg 4 must have quit at about day 10 or 11 I think and egg 3 had a fully formed chick inside must have Just not had the strength to hatch

I am glad you got 2..

And yep, you never know with incubation... some just don't hatch.