This is the 'Spindle Checkpoint' placed at the important point 'Metaphase-Anaphase Transition' in the post town 'M Phase' on the 'Cell Cycle Highway.' The mitotic spindles and chromosomes carried by the travelers are carefully inspected, and the travelers must be arrested until all the chromosomes have been aligned at the equator and all the pairs of sister kinetochores have been properly attached to the microtubules from both poles of the spindle to achieve bi-orientation. Only those who safely pass the checkpoint can enter the 'anaphase' of their trips.
One winter day when the snow covered the trees and the ground, a woman is taking out racks, in which frozen samples are orderly stored, from a liquid nitrogen cryogenic storage vessel with a dipper. There might not have been any satisfactory safety gloves at that time. Patterns of snow crystals are printed on her kimono sash.