Charlie and Rex head underground into the allegedly haunted Black Cove Mine after film crew member Jay Tomlinson turns up dead during a horror film shoot about a local legend of a killer mine worker named "Cold Heart" Caleb O'Connor.
Tropes:
- Adaptational Villainy: Murray Whitmore, a local antiquities dealer, angrily accuses the film crew of villainizing Caleb O’Connor and claims that he was just an ordinary hard-working man who did nothing wrong. His claims are revealed to be correct, as Murray is Caleb's great-grandson and knows the real story of what actually happened back then.
- Be As Un Helpful As Possible: The case ends up being hampered by the movie’s producer Gloria Hamlin, who writes about it on social media to promote the legend and obtain a bigger fanbase when the SJPD wanted to keep everything on the down low for the time being until they found Jay's killer.
- Death by Irony: Jay's cause of death was from an asthma attack brought on by inhaling mold spores in the mind, which actually contained healing properties that make them useful for making medicine. Jesse even name-drops the trope in the discussion about it.
- Does Not Like Spam: Jesse mentions during the conversation about Jay's cause of death that he has a dislike of mushrooms. They ruin pizza, and Smurfs live in them.
- Faking the Dead: Nell actually survived the cave-in. Charlie lies to Ian in the interrogation room about her death so the former can tell how he figured out the latter was behind Jay and Gloria's murder and tried to frame Nell for it while she listens on the other side of the two-way mirror. Nell responds with Tranquil Fury that the SJPD have her full cooperation in testifying against her husband in court.
- Foreshadowing: Charlie is told not to make any loud noises in the mine or the sound reverberations could trigger a cave-in. Nell calling out to Ian inside the mine ends up causing it to collapse with them, Charlie, Sarah, and Rex still inside. Fortunately, all of them are rescued before they run out of air.
- Frame-Up:
- Clarke is indirectly framed for Gloria's murder when Charlie catches him in the mine dressed up like Caleb, standing over Gloria’s body and then fleeing the scene. Ian was also responsible for Gloria’s death, as he killed her when she inadvertently caught him wiping his fingerprints from the crime scene when she went to meet up at the mine with Clarke that night.
- Ian tried to frame Nell for Jay and Gloria’s murder by planting her cell phone at the area of the mine where Jay’s body was found. However, he planted it after the forensics team already did a sweeping of the area, and they would not have missed it the first time they were there as Charlie and Sarah point out. This connects the placement to Ian storming out on Nell the night he went to wipe his fingerprints from the crime scene.
- From Bad to Worse: While investigating Jay's murder, things take a turn for the worse when Gloria is also found murdered in the mine the following night. It gets even worse the night after when Charlie, Rex, Sarah, Ian, and Nell are trapped inside the mine when it caves in around them. Fortunately, all of them make it out alive.
- Happily Married: Ian and Nell Silver are a young married couple who are both actors and investors in the movie, having become involved in it when they were facing financial troubles. Turns out Nell had also been having an affair with Jay through their so-called "acting classes." When Ian found out about it he went to confront Jay and murdered him, then framed his wife for it. To say Nell is not pleased with any of Ian's actions is an understatement, as the SJPD gets her full cooperation to testify against her husband in court.
- I Never Said It Was Poison: Charlie points out to Ian that in their final encounter in the mine the latter outed himself as Gloria's murderer when he inadvertently revealed that he knew where she died, as her killer would be the only one outside the SJPD to know that when all information pertaining to the crime was not made public due to the investigation still going on at the time.
- Missed Him by That Much: Charlie tries to contact Jesse when the former, Sarah, Ian, and Nell get trapped in the mine after it caves in. Unfortunately, Jesse was reading a book about Caleb and got freaked out by a part of the book so much that he put it down and left, leaving his phone behind just before it picks up Charlie's call. He eventually gets the message through Rex and gets Donovan to send out a rescue party.
- Murder by Inaction: When Ian went to confront Jay about the latter and Nell's secret love affair, he found him on the ground suffering from an acute asthma attack from the mold in the mine and was trying to get outside. Instead of helping him, Ian closed the doors to the mine and kept it shut until Jay finally asphyxiated and died, then dragged his body deeper into the mine where he could be easily found. Ian later faked a fight with Nell so he could storm out at night to cover his tracks and stole Nell's phone to plant it at the mine to frame her for Jay's murder.
- She Knows Too Much: After Jay's body was found and the mine became a crime scene, Ian went back later that night to wipe his fingerprints off the door only for Gloria to inadvertently catch him in the act when she showed up at the mine to discuss with Clarke about Caleb making a physical appearance in the movie, leading to Ian killing Gloria with the pickaxe she brought with her to keep her from going to the police when she realized what he was doing.
- Stealing the Credit: Clarke Maitland (the production assistant) was the original writer of the movie's script. He brought it to Jay, who made several changes and eventually removed Clarke's name from the credits and replaced it with his. Clarke didn't actually mind Jay doing that, as he admitted that the script became a lot better than what it originally was.
- Urban Legend: The movie being produced revolves around the local legend of "Cold Heart" Caleb O'Connor, a Black Cove Mine worker who in 1917 was said to have had gone crazy and killed several of his coworkers and disappeared deep into the mine, with his body having never been found. His actions resulted in the creation of the Black Cove Curse, where all who enter the mine have twenty-four hours to live, with there being numerous deaths over the years because of it. The real story is that Caleb was a beloved, hard-working man who was just trying to get the miners to unionize because he was tired of seeing them get hurt or killed due to unsafe working conditions. When Caleb realized that his actions would put a target on his back, he fled to another town under a new identity, met a woman, and told his descendants to keep what really happened a secret. All of the later deaths were from causes like air-depraved tight spaces and mold spores contaminating what little air there was inside the mine.
