Mad" Mary McArdle ( Seána Kerslake ), a young woman with a propensity for violent, antisocial behaviour , is released from prison following an assault on another woman at a club. Upon Mary's return to Drogheda to live with her mother and grandmother, she tries to reconnect with old friends and acquaintances. Mary learns that her best friend since childhood, Charlene ( Charleigh Bailey ), is getting married, and Mary spends a significant portion of the film writing her maid of honour speech to deliver at the wedding. However, as the film develops, it shows that there is a growing distance between Charlene and Mary, as Mary futilely attempts to arrange to spend time with an increasingly busy and uninterested Charlene. Mary signs up for a speed dating service to meet men with the sole purpose of finding a 'plus one' to accompany her at Charlene's wedding, but each date ends unsuccessfully, with Mary unable to connect with any of the m...