|Dates||???? - 2017 (killed by Sheriff Jody Mills)|
|Occupation|| British Men of Letters|
Headmistress of Kendricks Academy
|Episode(s)|| 12.17 The British Invasion|
12.21 There's Something About Mary
12.22 Who We Are
Hunters are dogs, Mr. Davies. You give them an order, and they obey. That's how it works. So tell me, do they? Do they obey you?
– Dr. Hess, 12.17 The British Invasion
Dr. Hess is the Headmistress of Kendricks Academy and a high ranking member of the London Chapterhouse. Highly strict and emotionless, she recruits new members for the British Men of Letters. The process includes having one recruit kill another in her office to enter the next phase of their training. Like Lady Antonia Bevell, she is a zealot who considers American hunters to be nothing but mindless brutes. Officially, she never leaves London, unless ordered to by the elders of the London Chapterhouse.
In 1987, Dr. Hess summons a young Mick Davies and his friend Timothy. She tells them that only one of them will be leaving her office to begin the next step of their training as a member of the Men of Letters. She leaves a dagger on the table before leaving the room. A few minutes later, Mick walks up to her with the dagger in his hand, covered in Timothy's blood. She compliments him on executing her orders without question.
In the present day while Mick was crashing in the Bunker, Dr. Hess calls him to remind him that he didn't send her his daily report. She appears to trust Toni Bevell's word over Mick's concerning the Winchesters. She announces that the situation concerning the unborn Nephilim has shifted the British Men of Letters' primary concerns away from recruiting the American Hunters to their cause. She orders Mick to control the Winchesters and the other hunters they have already recruited, or turn them over to Mr. Ketch and start fresh -- assimilate or eliminate. Clearly doubting Mick's judgement, she sends her operative Renny Rawlings to keep an eye on him, but he ends up dead.
After Mick returns from the hunt for Dagon and Kelly Kline, Dr. Hess appears to him at the mobile command. She wants him to go after Eileen Leahy and execute her for killing Rawlings; Mick tries to convince her otherwise, to no avail. She wants to study the Winchesters' behavior and execute them if they are found guilty. Mick, after realizing that the Code for the British Men of Letters is skewed, stands up to Dr. Hess and defends what the Winchesters do. He tells her that Toni Bevell had completely ignored all the good that the Winchesters have done and declares that he chooses to do the right thing, which immediately results in his death by Mr. Ketch under her orders. Dr. Hess announces that the plan to recruit American Hunters has failed and she wants Mr. Ketch to exterminate every single hunter, including Sam and Dean.
As she is organizing her files, Dr. Hess is visited by Crowley who applauds her for having her agents exterminate the American hunters. He reveals that it was he who provided Mr. Ketch with a hellhound. She reminds him that they will have the same arrangement in the United States that they already have in the United Kingdom: agreeing to share information and having the demons limit their involvement to making soul deals. They both agree to make their top priority locating Lucifer's unborn Nephilim son rather than conflicting against each other. Hess also wants Crowley to sever his relationship with Sam and Dean. Later, Crowley decides to use Lucifer as a weapon against the British Men of Letters, specifically Dr. Hess, calling her a "British bitch who's far too comfortable giving me ultimatums."
After berating Mr. Ketch about his relationships with Mary and Toni, she tells him that either he or Toni will become the administrator to the British Men of Letters operating in America.
Dr. Hess has a briefing with her agents about the targets that they will be eliminating, specifically Claire Novak and Garth. She tells them to kill all family members and bystanders, stressing that they do not want to leave witnesses. She is seen observing her agents preparing to head out to eliminate their targets.
Later, the compound is ambushed by a group of hunters led by Sam and Jody Mills. At one point, she kicks a gun out of a hunter's hand, snaps his neck, and sends him falling onto a glass table. Jody is able to catch up to her, but Hess shoulders her in the eye and retreats to her office. As she is contacting an elder in London who tells her that they don't have the resources to retrieve her, Roy is able to blast the door open, letting him, Sam, and Jody inside and holding her at gunpoint before she can grab her gun. As a last-ditch effort to convince them not to kill her, she hands Sam a file filled with photos of Lucifer exiting the Needham Asylum. She tells them that he is currently tracking Kelly Kline and Castiel, pointing out that he will be unstoppable if he gets his hands on the child. She tells them that they can't face that alone and that they need her. Sam, after careful consideration, declines her blackmail and shoots the computer monitor. Hess grabs her gun and aims at Sam, but Jody shoots her in the head, killing her and avenging Mick's death. After taking the file on Lucifer, Sam and the rest of the surviving Hunters destroy the compound, along with her body, as they vacate the premises.