While Rundle's early career is dominated by period dramas and crime shows, in between 2012 and 2015 she flexed her comedic chops in two comedies: Episodes and Not Safe for Work. Her first comedic role was certainly a memorable one.
In seasons 2 and 3 of Episodes, she appeared as Labia, Matt LeBlanc's unfortunately named stalker, who he first met as a Make-A-Wish child when she was eight. As an adult, Labia becomes obsessed with Matt, and often breaks into his home to do random things like bake cookies naked in hopes of impressing him. It's a complete departure from Rundle's previous work, and the role showed she's just as adept at being funny as she is at taking on serious characters.
After Episodes, she briefly returned to the world of crime dramas with a small role in season 1 of Sally Wainwright's Happy Valley, and gave a powerful performance as a mother suffering from postnatal psychosis in a season 3 episode of the long-running series Call the Midwife. Then, in 2014, she made a rare film appearance in the psychological drama The Face of an Angel, alongside Kate Beckinsale and Cara Delevingne.
By 2015, she was ready to take on another comedy, and this time she played the perpetually peppy Jenny on Channel 4's Not Safe for Work. The short-lived series focused on a civil servant who is forced to relocate from bustling London to the small town of Northampton, where she works alongside people who are used to a much slower pace at work, like Jenny, who has never ventured beyond her hometown.