"My usual plays are what I would term mature-age romantic comedies, which deal with relationship issues of people in their 60s," Charteris said.
"But I'd wanted to write a thriller for some time and I chose this topic – the death of a terminally-ill woman – as the starting point to see how I could develop a plot with many twists and turns.
"In comedy, you have much more poetic licence to create characters but with a mystery play, the roles have to be believable and the plot also has to stand up to scrutiny."
"Many people have been touched by suicide and I witnessed a very close friend trying to cope with the devastating effect it has on immediate family and friends," Byrne said. "Teenage suicide is a blight on our society and I wanted to raise awareness of this in what I hope is an engaging way."