The Doctor has managed to get the TARDIS to take him and Jo to Estringokl, where he hopes to show Jo the festival of Planetfall. However, they are faced with a blizzard and an ice-covered planet. The Doctor feels that something is calling him, so he ventures outside, after donning weather-appropriate clothing. He heads back to the TARDIS to tell Jo about the tree, and he takes the TARDIS to the next ten Christmases. The first four, he does the job alone, but Jo convinces him to let her help after that.