It's the question many fans wanted the answer to going into Happy Valley's finale and, after it was left unanswered in the last episode, the mystery of why Poppy never takes her coat off has been explained, by another cast member.
While the focus of the last series of the BBC drama has been very much on the stormy feud between Catherine Cawood and Tommy Lee Royce, there was a sub plot involving Poppy's dad. teacher Rob Hepworth and his wife Joanna, who became hooked on prescription pills and was shopped to the police by her husband, before being killed by corrupt pharmacist Faisal Bhatti.
The couple's two daughters witnessed a lot of the tension between their parents and the aftermath of Rob calling the police on Joanna and her disappearance, with her body eventually being found in a suitcase.
