RUBY Clarke's diary may be filled with rehearsals for York Shakespeare Project's Timon Of Athens, but the director and playwright has another show in York to squeeze in before her May production.

"I wrote a play for Postcard Theatre last autumn and they have managed to get it over here on April 1 and 2," says Ruby, as the premiere tour of Border Line heads for Friargate Theatre next week.

"The show is a contemporary dark comedy about the fine line between affection and stalking, where the behaviour of the obsessive character, Stella, isn't necessarily seen as stalking according to the law, which is the point of the play."

In Border Line, Claire (played by Jenny Owen) has never liked confrontation, preferring to do whatever it takes to keep people happy. A new job allows her to move away from an uncomfortable relationship, but she brings with her an inability to confront issues head on, a trait her best friend has always said would be her downfall.

At work, she is befriended by new colleague Stella (Julia Walsh). Stella, however, turns out to be an oddball with a lack of understanding of normal social etiquette, but that does not stop her trying to help Claire with whatever she might need, and Claire begins to question her motives.

Long-time friend Jackie (Amey Woodhall) encourages her to take a stand and not shy away in fear of causing offence, but as events turn graver, Claire does not know how much more "friendship" she can take.

"Claire finds herself in a predicament of politeness," says Ruby. "She struggles to know where to turn for help as the line between friendship and something altogether more sinister becomes blurred. When things begin to fall out of her control, she may have to take matters in to her own hands."

In looking at the grey area surrounding the laws and conceptions of stalking, Ruby considers how this can affect the lives of those involved.

"I'm exploring the rule-less nature of friendship, and the dangers that can arise from there not being a set formula to play by," she says. "Where does a person turn when a seemingly harmless friendship starts to feel obsessive and unhealthy, and what defines the difference between the two?"

Border Line forms Postcard Theatre's third production in 12 months after the play collection When The Rich Wage War, It’s The Poor Who Die and Luke Barnes's Chapel Street. Ruby handed over the script to director John-Mark Reid last September, since when he has been developing the play. After York, it will play Salford and Preston.

In York, Ruby has directed The Mercy Seat, Quicksand and Night Of The Barghest; in 2013, she was artistic director of York Theatre Royal's TakeOver Festival and last year she was chorus director for the York Guilds' York Mystery Plays on pageant wagons.

Timon Of Athens will run from May 14 to 17 in the De Grey Rooms Ballroom as part of the York International Shakespeare Festival.