Does Harry Potter series' Moaning Myrtle actress Shirley Henderson feature in Dept. Q? Details explored 

Dept. Q features a unique ensemble of cast, such as Matthew Goode, Alexej Manvelov, Leah Byrne, Shirley Henderson, and more. Created by Scott Frank and Chandni Lakhani, it is an adaptation of the Nordic noir crime novels, Department Q, by Jussi Adler-Olsen.

Actress Shirley Henderson, known for her role as Moaning Myrtle in Harry Potter, appears in the Dept. Q as Claire Marsh.

The series follows Carl Morck, an English detective who returns to a new police department after his traumatic experience in a past case. Despite his assertive persona, his skills and intelligence set him apart, making him the leader of the new 'Dept. Q' dedicated to solving cold cases. Shirley Henderson plays the role of Claire, a housekeeper and caretaker of William Lingard, Meritt's brother.

Disclaimer: The article contains spoilers for Dept. Q and the Harry Potter series. Reader's discretion is advised.

---

Shirley Henderson, the actor behind Harry Potter's Moaning Myrtle, plays the role of Claire Marsh in Dept. Q

A still from Dept. Q (Image via Netflix)

Scottish actress Shirley Henderson has been a popular face in the wizarding world of Harry Potter as Moaning Myrtle. She has also portrayed the character of Claire Marsh in Netflix's Dept. Q.

Claire is a house nurse for William, Merritt Lingard's brother. The missing case of Merritt Lingard, which DCI Morck takes up first for his team, has a strong connection with Willian and Claire.

William had suffered a severe injury to the head in the past, making him cognitively impaired. Since then, Claire takes care of him at home while Merritt pursues her career as a prosecutor. Later, during the Lingard siblings' boat ride, Merritt and William have an intense altercation after which the former goes mysteriously missing.

Claire is a simple and observant person who is dedicated to taking care of William. Even after William moves to Egley House Hospital post Merritt's disappearance, Claire makes regular visits to William. After several attempts, Carl and Akram push her to tell all that she knows about the case. She tells them about William's innocence and the siblings' bond. The character also appears in many other key moments in the later parts of the series.

---

Shirley Henderson describes her character in Dept. Q

A still from Dept. Q (Image via Netflxi)

Shirley Henderson gave a glimpse of her character, Claire, and spoke about her experience of working on the show at the U.K. Premiere of Dept. Q. In an interview with HeyUGuys, released on May 28, 2025, the actress shared details about her journey with the new Netflix series.

Talking about how she felt about filming in her home country, Scotland, Shirley said:

"Really nice. Unexpected. Scott Frank is, I think he is a genius. I think he's very just so easy to work with. Brilliant ideas... just makes it all... you just want to work more and more with him. And it is very nice to be at home, and familiar territory, and working with people that I have admired and respected for a long time."

Describing her character in Dept. Q, the actress mentioned:

"She's a housekeeper, and so she's an observer. She's very quiet and kind of just there, looking after William Lingard. Tom Bulpett plays William. We'll see what happens with her. She's a thinker. I think she's got her thoughts. She's on the edge. She's on the outside slightly. Things have happened to her a long time ago."

---

Shirley Henderson as Moaning Myrtle and her other works

Shirley Henderson as Moaning Myrtle in Harry Potter and the Goblet of Fire (Image via Max)

Shirley Henderson is known for playing the role of Moaning Myrtle in the Harry Potter movie series. She is part of Harry Potter and the Chamber of Secrets (2002) and Harry Potter and the Goblet of Fire (2005).

She first appears in the series when Harry, Ron, and Hermione prepare the polyjuice potion to disguise themselves and question Malfoy about the chamber. Moaning Myrtle also informs Harry about her tragic death, which helps him find the way to the Chamber of Secrets from the second-floor bathroom. Shirley later appears in the fourth part, helping Harry in opening the golden egg for the next task of the Triwizard tournament.

Henderson has delivered prominent performances in other projects, such as the Bridget Jones films (2001-2025), The Way We Live Now (2001), Miss Pettigrew Lives for a Day (2008), Star Wars: Episode IX - The Rise of Skywalker (2019), The Mandalorian (2023), and more. She has several accolades credited to her name, such as the BAFTA Scotland Awards, VFCC Award, SPIFF Awards, and more.

---

Watch Shirley Henderson in Dept. Q on Netflix.