On silent snowy nights, when no sounds can be heard, many people go deaf in one or both ears. The doctors can't do anything, so they think it might be paranormal. Ginko looks into some of the villager's ears and he tells them that the cause is a Mushi called "Un". After dealing with their small problems there is one more person who has lost sound in both of his ears and his condition is very different than the other people's, as he has also grown four horns on his head.

Ginko is waiting along the sea shore, for a transport to get him across the bay when he meets a man called Shirou, who lost his wife under strange circumstances. Ginko seems interested and decides to listen to his story about how he lost his wife in a swarm of sea snakes, during fog. Ginko later comes back with information on the Mushi that caused the bizarre events.

Some kids enter Adashino-sensei's shed and find a lot of strange things, but there's one thing in particular that interests them. It's night and Adashino-sensei is called upon to look at one of the kids, a girl who has become bitterly cold, and the cause is a mysterious ink stone she touched. Luckily for Adashino-sensei, Ginko is passing through the village, and he shows him the ink stone, which he identifies it as a "Kumohami".

"When all are sheltering within, there comes an imitation of spring. Linger in bliss for too long and your flesh will soon be frozen..."

Caught in a blizzard, Ginko is decides to look for shelter and finds a home where the owner, Suzu allows him to stay the night. The next day Ginko sees a boy, Miharu who seems to be fascinated by Mushi. Ginko learns that Miharu once disappeared into the mountains in the winter and then suddenly came back in spring, able to see Mushi. Miharu has been repeating this since and it may be caused by a "Harumagari" so in the end, Ginko decides to teach him more about Mushi.

It is spring, and Ginko is taking a boat through a river, when the boat's boy, Kaji, asks Ginko whether he could help his mother, who's forgetting things and can't sleep. At first glance it may appear to be progressive amnesia, however something isn't right.

Ginko arrives at a secluded place, to meet an old acquaintance, who seems to be in charge of a large volume of archival, confidential text. Ginko is allowed to read it, and discovers it is the work of Tan'yu, a writer. Tan'yu is the descendant of the Karibusa family, being born with a black mark on a part of their body.

"Build a fire - night comes... Light a fire - darkness comes... Hide the fire - flames arisen from corpses creep in..."

Ginko meets another Mushi-shi, which happens to be a young lady called Yahagi and surrounding the village she lives in is a new variety of Mushi growing on the mountain's fields. It's becoming so bad that the village people are at risk and as a last resort they plan to burn the entire mountain but Ginko doesn't think that this is the right option.