Googled and found this:
The Channel 5 drama "The Vanishings" (originally titled "The Vanishing Triangle") is based on a true story involving the disappearance of women in Ireland's "Vanishing Triangle". While not explicitly a hen weekend scenario, the show features a group of women who are connected to the disappearances, and the investigation is led by a journalist investigating her mother's murder, which is then connected to the missing women. The show is a dramatization of the real-life cases, and while the specific details may differ, the core theme of missing women and a potential serial killer is present,