Wow, that sounds serious!
And that "Christmas Alien egg" looks just like what I found! Must be the same issue. I'd be interested to know how it turned out for the people who found that, if their chicken died or not. I'm wondering now what antibiotics to treat the hen with, once I narrow it down to which one I think it is? And what the dosage might be? Unfortunately I don't know of an avian vet to ask these questions! I might have to go buy that old issue and take a look at the article since it obviously seems to apply to this case.

My other question would be, was the mass what caused the infection, or did she have an infection that caused the mass? If she passed the mass is she out of immediate danger of death for the time being?
The one who passed the mass was one of two possible culprits in my henhouse. Since I have a small flock I'm pretty good about keeping an eye on individual chickens and their habits.
The hen I thought most likely was the one with problems is a black sexlink that has been having shell issues since I got her. She lays an egg almost daily, and maybe 75% of the time it is thin-shelled but normal. The rest of the time she lays a soft-shelled egg. I've given her vitamins and extra calcium before in case it was a deficiency, but they had no effect. She also lays double-yolked eggs pretty often but not all the time, maybe twice a month or so? I assumed it would be her with the problems but she is behaving normally today, has a very bright comb and is eating. She also laid a normal egg today.
The other hen that might be the one is a rescue, and I haven't been able to figure out if she's ever laid an egg or not. If she did she started right around when my new pullets started laying theirs, so I am still trying to be sure who's laying which egg. The only reason I suspect her is that today she didn't eat, even when I threw some corn out for them. She's also acting a little lethargic, but she's at a good body weight and has a VERY bright colored comb.
I guess it could be any one of my new pullets too, but they are also acting normally today. Are there any other signs to check for to determine who has the infection?