Pauline Duquette is the main villainess from the 2015 Hallmark film, The Gourmet Detective.
She was played by Laura Mennell, who also played the evil Brigitta on Supernatural's sixth season opener.
Pauline Duquette is the niece of Peter Duquette, who owns Chez Duquette and is a longtime friend of the titular "Gourmet Detective," Henry Ross. She is also the girfriend of Layton Leonard, the chef at Fillmore Bistro (the rival restaurant of Chez Duquette), and the couple conspired together in a plan to build their own food empire.
The plan involved Pauline and Layton sabotaging their respective restaruants, which would lead to Peter and Raymond Fillmore selling to them at a good price. However, they were caught together by news reporter Ian Jenkin, and that prompted Pauline to kill Ian to keep him quiet. The villainess poisoned Ian's dish at a gathering at Chez Duquette, using a chemical known as TTR (which is has a resemblance to botulism) to commit the murder. Ian succumbed to the effects and died just as he was about to reveal Pauline and Layton's scheme. Layton began panicking following Ian's murder and developed cold feet, and following this, the evil Pauline killed him with the same poison. She used spliced recordings of Layton and left it as a "last word" to set up the murder as a suicide.
The recordings revealed Pauline as Layton's accomplice and as a murderess, as Henry (who was working the case with Detective Maggie Price) noticed that the supposed single recording had separate hourly chimes: one at 1:00 and one at 2:00. The pair also found a flash drive in Layton's home, which had belonged to Ian, and it showed the villainous couple at a nearby bank kissing. In the film's climax, Henry and Maggie went to the Duquette home, where the latter was set to arrest Pauline. However, Pauline pulled out her uncle's gun and pointed it at both of them, while ordering Maggie to hand over her own gun and handcuff herself to the radiator. She later took Henry hostage and ordered him to go downstairs to the kitchen; unaware that Maggie had freed herself.
With the police surrounding her, Pauline threatened to kill Henry if they moved closer. At that moment, Henry told Pauline to think of Peter and her family's restaurant, while also stating to Pauline that she was the daughter Peter never had. Pauline put down her gun and was later handcuffed and arrested, all while claiming that she didn't mean to let things get out of hand.