Upon arriving in Montana, Luke and the player went to Roundhead Lake after hearing that the locals had found the body of a farmer allegedly killed by the lake monster Hannah. They then found Wyatt Ewing stabbed in the neck with a three-pronged implement.
Mid-investigation, the team calmed down a mob of farmers, who wanted to destroy Hannah before it killed anyone else. They then found a threat from the killer, confirming that Wyatt was murdered by a human, not killed by Hannah. Later, farmer Blake Woodbine's goose, Lordy Gaga, bit Luke and stole the keys to his RV. The team then found enough evidence to arrest shopkeeper Poppy Winters for the murder.
Poppy said that Wyatt had wanted to drain Roundhead Lake, which was in his property, so he could grow more crops. Worried that it would kill Hannah, Poppy tried to dissuade him from pushing through with his plan, which did not work. To save Hannah, Poppy stabbed Wyatt in the neck with a trident. The team then took Poppy to the authorities before informing the townspeople of her crime.
Post-arrest, Priya told Luke and the player that she had seen Arthur Darkwood holding meetings with Annette Strong and heard that Arthur was the one sending the team threatening messages, which meant he was a demon. With Arthur recently staying the night in Wyatt's bed and breakfast, they searched the ranch for proof of his identity. There, they found Arthur's notebook which contained undeniable proof that he was a demon. Furthermore, he had written something about a magical tree in Yellowstone. The team then confronted Arthur, who admitted to it and claimed he was only trying to protect the team. Arthur then said that he crossed over to Earth without any summoning far longer than five years prior. He then warned them to stay away from the tree, telling them that "it was dangerous enough for the werewolves" before disappearing in a puff of sulfurous smoke.
Meanwhile, Zeke Davis reported that he saw Hannah emerge from the water. Felix, Zeke, and the player were then able to talk to Hannah via a makeshift voice converter, and even returned to her a pearl necklace that Wyatt had stolen from her. Hannah then thanked the team, telling them that they only needed to call her and she would come to their rescue.
After all the events, Felix announced that he had found the magical tree in Yellowstone, and so the team headed there to pursue their lead.
- Wyatt Ewing (stabbed through the neck by Roundhead Lake)
- Poppy Winters
- The killer eats lakeweed.
- The killer goes underwater fishing.
- The killer has watched Ridgeback Mountain.
- The killer wears tartan.
- The killer has green eyes.
- Investigate Frozen Lake. (Clues: British Passport, Victim's Coat, Victim's Body; Victim identified: Wyatt Ewing)
- Examine British Passport. (New Suspect: Mimi McPhee)
- Question Mimi McPhee about the murder. (Prerequisite: Mimi McPhee identified; New Crime Scene Unlocked: Barn)
- Investigate Barn. (Result: Goose [Goose Tag], Crate of Seeds)
- Examine Goose Tag. (New Suspect: Blake Woodbine)
- Ask Blake Woodbine if he knew the victim. (Prerequisite: B Woodbine decoded)
- Examine Crate of Seeds. (Result: Pamphlet; New Suspect: Fabian Roland-Tavin)
- Ask Fabian Roland-Tavin what brings him to Montana. (Prerequisite: Pamphlet found)
- Examine Victim's Coat. (Result: Slimy Substance)
- Analyze Slimy Substance. (03:00:00; Attribute: The killer goes underwater fishing)
- Autopsy Victim's Body. (18:00:00; Attribute: The killer eats lakeweed)
- Go to Chapter 2. (1 star)
- Investigate Winter Ranch. (Available after unlocking Chapter 2; Clues: Mailbox, Ripped-up Toy)
- Examine Mailbox. (Result: Threat)
- Analyze Threat. (03:00:00; Attribute: The killer has watched Ridgeback Mountain; New Crime Scene Unlocked: Lakeside)
- Investigate Lakeside. (Prerequisite: Threat analyzed; Clues: Camera, Wooden Sign, Magazine)
- Examine Camera. (Result: Victim's Camera)
- Analyze Victim's Camera. (09:00:00)
- Find out if Mimi McPhee knew the victim had been ogling her. (Prerequisite: Victim's Camera analyzed; Profile updated: Mimi goes underwater fishing and has watched Ridgeback Mountain)
- Examine Wooden Sign. (Result: GrimFoods Sign)
- Question Fabian Roland-Tavin about the GrimFoods sign. (Prerequisite: GrimFoods Sign unraveled; Profile updated: Fabian eats lakeweed)
- Examine Magazine. (Result: Rubble)
- Examine Rubble. (Result: Lizard Poo; New Suspect: Zeke Davis)
- Ask Zeke Davis why he's in Montana. (Prerequisite: Lizard Poo identified under microscope; Profiles updated: Zeke goes underwater fishing and has watched Ridgeback Mountain, Blake has watched Ridgeback Mountain)
- Examine Ripped-up Toy. (Result: Plushie; New Suspect: Poppy Winters)
- Talk to Poppy Winters about the murder. (Prerequisite: Plushie restored; Profile updated: Poppy eats lakeweed and goes underwater fishing)
- Go to Chapter 3. (1 star)
- Investigate Haystack. (Available after unlocking Chapter 3; Clues: Faded Paper, Victim's Phone, Broken Frame)
- Examine Faded Paper. (Result: Restraining Order)
- Analyze Restraining Order. (09:00:00)
- Question Zeke Davis why the victim took out a restraining order against him. (Prerequisite: Restraining Order analyzed; Profile updated: Zeke eats lakeweed)
- Examine Victim's Phone. (Result: Voice Message)
- Find out what the victim owed Poppy Winters. (Prerequisite: Voice Message unlocked; Profile updated: Poppy has watched Ridgeback Mountain)
- Examine Broken Frame. (Result: Photo of Blake)
- Ask Blake Woodbine why his photo was broken. (Prerequisite: Photo of Blake restored; Profile updated: Blake eats lakeweed and goes underwater fishing)
- Investigate Front Yard. (All tasks before must be done first; Clues: Winter Accessories, Swimming Fins)
- Examine Winter Accessories. (Result: Trident)
- Analyze Trident. (09:00:00; Murder Weapon registered: Trident; Attribute: The killer wears tartan)
- Examine Swimming Fins. (Result: Skin Cells)
- Analyze Skin Cells. (15:00:00; Attribute: The killer has green eyes)
- Take care of the killer now!
- Go to The Call of the Wild (4/5). (No stars)
The Call of the Wild (4/5)
- Answer the call from Priya. (Available after unlocking The Call of the Wild; Reward: Lake Monster Scarf)
- Investigate Winter Ranch. (Prerequisite: Priya interrogated; Clue: Planner)
- Examine Planner. (Result: Planner)
- Analyze Planner. (09:00:00)
- Confront Arthur Darkwood about being a demon. (Prerequisite: Planner analyzed)
- Go with Zeke Davis to meet Hannah, the lake monster. (Available after unlocking The Call of the Wild; Reward: 20,000 Coins)
- Investigate Barn. (Prerequisite: Zeke interrogated; Clue: Cow Accessories Box)
- Examine Cow Accessories Box. (Result: Cow Collar)
- Analyze Cow Collar. (06:00:00)
- Use the voice converter to communicate with Hannah. (Prerequisite: Cow Collar analyzed; Reward: Burger)
- Investigate Front Yard. (Prerequisite: Hannah interrogated; Clue: Well Bucket)
- Examine Well Bucket. (Result: Necklace)
- Move on to a new crime! (1 star)
- The case title is a reference to Winter Wonderland, a song written in 1934 by composer Felix Bernard.
- Roundhead Lake is a parody of Flathead Lake, a large natural lake in northwest Montana.
- Ridgeback Mountain is a parody of the 2005 film Brokeback Mountain, originally a short story by Annie Proulx.
- Lordy Gaga is a parody of Lady Gaga.
- In Chapter 2, a lake monster magazine mentions a headline, "Mythical lake beasts and where to find them". This can be a reference to the 2016 film, Fantastic Beasts and Where to Find Them, originally written as a Harry Potter guide book by J.K Rowling.