My coops are in my big building that I use for a tack/buggy building for my horses. The chicken coops are at the very back, with people doors from the the tack area and little chicken doors on the sides for them to go out. I opened the people door and then walked to the front of the building and opened the big garage door and it was out of there before I could turn around. It had to have walked in the little chicken door that I forgot to close last night.
I can't believe there is only one pullet missing. I'm as sure as I can be that she isn't dead.