I find this very amusing. It starts with a Sister going missing, while searching for her at her work place, focus get's lost more and more, most of the time it's "no, no, concentrate on your mission to find your Sister..." but at the end she doesn't even see her anywhere, not at home, not in the Lab or even in the Mirror. Then all are saved at she stands somewhere around the Group as if she was part of the Adventure all along. The Question I have now is: Was she also in the Mirror and sleeping like the others? or was she actually stuck somewhere in the Lab or went out of the Lab when things went wrong and just then returned as everyone got freed since she did get the message to gather at Wingdings floor on floor ten and maybe just decided "meh, nobody's gonna notice if I pretend to go to the Toilet to out to grab some food/snack/starbucks"