kirk and crew land on a lonely planet where the sun be about to explode . they intend to evacuate the inhabitant but find the place desert except for a mr. atoz who operate some sort of high tech library . despite try to get a straight answer from him about everyone whereabouts and atoz be indifferent to their question and insist they must quickly amake a selection while there be still time . they have no idea what he talk about but wander about look at the hand mirror like disk on the viewer and they see image of the planet past . then and while a disk be in the viewer and kirk run through the doorway and be magically transport back in time to what on earth would look like the time of louis xiv ( the 1660s ) . when mccoy and spock follow and a different disk be in the viewer and they be send to an ice age hell . all too late they realize that the library be a time travel machine and repository . while kirk visit be pretty short and not all that excite and spock and mccoy be much more eventful and a spock fall head over heel for mariette hartley who be send to this awful place a a punishment . the scene with spock be exceptionally interesting and very atypical of the normally logical guy . spock departure from the norm and the wildly inventive script and very diverse locale make this an exceptional episode one well worth see . fyi ian wolfe and the excellent character actor and play mr. atoz . i be a huge fan of old film and have see him a a supporting and bit player in countless film in the 30 and 40 and he look almost exactly like he do in this episode from 1969. interestingly enough and despite look ancient and he live on another 23 year die at over 95 year of age .