In the next Snowfall journal entry, she arrives in the Frozen North and seeks a guide to Tambelon. She meets a donkey named Bray who offers to lead her there.
Diamond Tiara, Sweetie Belle, and Button Mash arrive in Trottingham and at the home of the Banks Family. Pence and Penny are thrilled with the visitors but their parents and cold an unresponsive, even refusing to divulge their names. The trio are instructed to only address them as Mister and Missus Banks.
Button, while searching for Mr. Banks’ liquor stores to replenish his flask, is met by Diamond Tiara in the kitchen. It’s here that we learn Button and Diamond Tiara’s secret; earlier in the year, the two had a one night stand due to Button’s drunkenness and Diamond Tiara’s heat cycle. Button reminds Diamond Tiara that they promised never to talk about it. They part awkwardly, each terrified that the other will tell Sweetie Belle.
Pence sees his parents fighting about the guests and hears how poor the family has become due to the bit crisis. He hides the information from Penny and doesn’t notice when she steals the letter to Santa Hooves.
As the family and guests sit around the fire, Sweetie Belle is drawn into an argument with Mr. Banks after he cruelly mocks Pence’s belief in Santa Hooves, telling him he needs to “grow up.” Pence talks back to his father. A drunken Button Mash stumbles in and says that the kids would respect their parents more if they knew about Grogar. As a horrified Diamond Tiara and Sweetie Belle look on, he tells the ram’s legend as Granny Smith told it to him. Pence and Penny are horrified and Mr. Banks demands the trio leave at once. While Diamond Tiara tries to reason with her cousin, Penny gives the letter to her mother. Pence watches in shock as his mother reads it, including the note at the bottom wishing that Santa Hooves can make their family happy again. Mr. Banks scoffs at the very idea and flatly tells Penny that there is no Santa Hooves. Furious at his father, Pence snatches the letter back and destroys it, ranting and crying about how excited he was to finally have a big family Hearth’s Warming but his dreams have been ruined. The blizzard outside gets worse and the trios shares a look. Sweetie Belle desperately tries to calm Pence but he finally declares his hatred of Hearth’s Warming. A resounding THUD comes from the roof and the fire dies. Before anyone can react, chains shoot down the chimney and grab Mr. Banks. Before he can be snatched away, Mrs. Banks grabs him and tries to pull him back. Instead, she gets pulled out with him. Panic descends on the five remaining ponies.
In Fillydelphia, 12 hours earlier, the doctor discovers that Applebloom has escaped. What’s more, he finds a hidden mural of Grogar on the wall formed from the repeated phrase ‘For Goodness Sake.’
In the third entry from Snowfall’s journal, she has been searching for Tambelon with Bray for several weeks. One night, she wakes up to find Bray in the midst of an arcane ritual. When he sees her watching, attacks but is easily subdued. When pressed, he claims to serve the Lord of Tambelon, the Master of the Windigos. He runs and leaps off a cliff, claiming that the wind will save him. It doesn’t. Shaken, Snowfall continues on alone.
Back in Trottingam, the upstairs windows shatter. The trio realize that Grogar is taking no chances this time and has brought helpers. The helpers are the children Grogar has snatched over the years. The trio and the two foals barricade themselves in the kitchen with the helpers attacking from all sides. Pence collects his wits enough to reveal the dumbwaiter that leads to the second floor. Pence and Penny are ushered up by Diamond Tiara. Before she follows, she and Mash blurt out their secret at the same moment. Sweetie Belle admonishes them both that it isn’t the time and she’ll be angry later. Diamond Tiara follows her cousins up. Button sees the helpers breaking down the door and closes the dumbwaiter door behind Sweetie Belle. The helpers break through and swarm Button, eventually overwhelming him. They chain him and drag him up the chimney to his fate.
The four remaining ponies huddle upstairs and are horrified when another pony appears from the snow. It is Applebloom.
In the final entry from Snowfall’s journal, she explains that she found Tambelon but was beset by Windigos. Desperate to save herself, she opens a sealed door in the center of the ancient city and barricades herself inside. As she climbs the great tower, she sees a huge mural detailing the legend of Grogar. He was a sorcerer who sacrificed the rams of Tambelon to become immortal. His cold heart transformed him into a beast of his former self and it was only the Princesses that were able to seal him away in another world before he could seize Equestria. At the top of the tower, Snowfall finds a huge bell inscribed with the phrase ‘For Goodness Sake.’ Unable to stop herself, Snowfall rings the bell. She remembers nothing of what happened next, only that she awoke far from the city with a much smaller bell in her possession. She declares that she must inform Equestria of the monster before he can return.
Applebloom surprises the others by declaring she knows how to stop Grogar. She boldly leads them back downstairs to the fireplace. When Diamond Tiara presses her, Applebloom finally declares that she knows why Applejack’s sacrifice didn’t work; it has to be an equal exchange. She says that now that Grogar has taken the Banks’ and Button, she can have her family back. Diamond Tiara realizes that Applebloom has actually gone crazy and tries to stop her. Sweetie Belle breaks up the fight but it is too late; the conflict has drawn Grogar. He comes down the chimney and Applebloom boldly proposes the trade. Grogar speaks, declaring that her heart is now as cold as his is. He blows an icy wind that freezes her and changes her into a Windigo. That taken care of, he advances on the remaining ponies. Diamond Tiara tells the others she’s sorry and goes to Grogar willingly. She says that she finally understands Applejack’s sacrifice and embraces the ram, wishing him a Happy Hearth’s Warming. The warmth of her love and her willingness to sacrifice herself burns Grogar and he once again flees before he can be fully defeated. The remaining ponies see him flying away on a sleigh drawn by Windigos. Sweetie Belle and the twins step outside to find that Trottingham, like Ponyville, has been frozen.
The next day, the twins are found by investigators from Canterlot. Sweetie Belle has frozen to death, having used her magic to keep the twins warm through the night. Celestia hears the report and afterwards discusses the situation with Luna. Luna suggests going and sealing Grogar up once again, but Celestia reveals that she already went to find Tambelon and that the great bell has been cracked by a magic spell. She says that she sees now that nothing can stop the spread of Grogar. He is like a virus and “belief gives him teeth.” Once somepony knows about him, all they have to do is doubt the magic of friendship on Hearth’s Warming and he is called. It will take time, but eventually all of Equestria will become as Ponyville and Trottingham are; a frozen wasteland.
All because a foolish unicorn rang a bell.
“Because of you Snowfall Frost, the future is a cold nightmare...”