The best crime TV shows tap into our worst nightmares. On Medium, those nightmares became a pivotal part of the show, as the psychic at the center of Medium's universe, Allison Dubois, receives her visions through her dreams, which in turn help her partner with police to solve crimes.

These visions are, of course, special. They give Allison clues, inviting her to witness past events and even giving her glimpses of the future. Unfortunately for Allison, though, both the past and the future are haunted by their own demons, which makes it doubly hard for the psychic to sleep. Nearly every episode features that familiar scene of Allison jerking awake, trying to make sense of the senseless crimes she encounters in her dreams.

But while Allison would likely see each dream as equally eerie, taking in these dreams as viewers, some dreams are undeniably more horrifying than others. While it's offputting, for sure, when Allison dreams she's in a plane that takes a nosedive, and, yeah, we would be weirded out if we dreamed up our own doppelganger, out of all of Allison's dreams, these are the most chilling ones that actually might've kept you up at night...

A DOCTOR WHO BUTCHERS TEEN PATIENTS - "Penny for Your Thoughts"

In the first season of Medium, Allison has a nightmare that features a doctor who she watches brutally murder a teenage girl on his operating table. It's gruesome and shocking to watch play out, but it gets even more ominous when even the visionary Allison can't identify the other man in the room.

THE LITERAL APOCALYPSE - "Apocalypse ... Now?"

Allison briefly becomes a survivalist after she has this shocking nightmare that shows the apocalypse is coming. Her dream features a man with a teen girl living out of a bomb shelter, with the man using a bio-hazard suit to help them survive and the girl issued a strict warning not to ever leave the bunker. For Allison as a mom, the dream is scary enough, but when that exact girl shows up with her throat slit the next day, Allison has to figure out the meaning of her dream to help solve the murder.

ALLISON'S WORST NIGHTMARE - "Bring Me the Head of Oswaldo Castillo"

While not all of Allison's dreams affect her personally, the ones that do are particularly triggering for the character, especially "Bring Me the Head of Oswaldo Castillo," the final episode of season 5. In it, Allison dreams that her entire family is brutally massacred by an assassin sent by a Mexican drug cartel.

As Allison tries to figure out how to keep her family safe from her nightmare, she also has to deal with the frightening reality that her visions of the future might be over completely. That makes this Allison's worst nightmare in terms of personal stakes involved.

DOUBLE NIGHTMARE - "Mother's Little Helper"

On Medium, Allison wasn't the only one experiencing psychic dreams. Her daughters were also troubled by them, especially Ariel, who shares in the terror of "Mother's Little Helper." The episode finds Ariel and Allison both scarred by the same dream after discovering a mother and daughter murdered in a dress shop. The twist is that Ariel's dream is seen through the eyes of the slain teen, and Allison's through the murdered mom. That means mother and daughter must work together to crack the code on the dream, and Ariel's more concerned with a school dance than helping her mom solve crimes, which results in this gruesome scene inspired by Carrie.

DEMONIC STALKER - "The Devil Inside"

This nightmare was so scary, they needed twice the time to tell it. In the two-part episode "The Devil Inside," Allison meets a man in her dreams who believes she is the devil. Even worse, he's on a mission to eradicate Allison's abilities, supposedly sent by God to strip her of her supernatural talents. As tends to happen on Medium, Allison soon meets this man in the real world, and it turns out he is a stalker who has a shrine to Allison, and his fascination has also been extended to her daughters. It's a squirm-filled, deeply troubling two episodes, and the nightmare doesn't even end when the stalker's life is cut short.

In the second part of the episode, Allison has to deal with the ghost of her stalker, still haunting her nightmares and taunting Allison with the threat that he's manipulating her dreams to mess with her. It's the scariest story to come out of Medium, introducing some of the most doubt we see in Allison Dubois when it comes to trusting her visions.