‘Drop’ has several undercurrents which relate to questions of domestic violence, the risks that come with blind dates, and the fear and guilt associated with leaving one’s child at home. It’s an exploitative set up, from the director of ‘Happy Death Day’, though it also works as a clever, intricately plotted study of psychological manipulation, and an updated version of Hitchcock’s ‘Strangers on a Train’ involving one character being blackmailed into committing the murder of someone they know next to nothing about in order to survive the evening.

Hitchcock would have relished a world of CCTV cameras and digital online surveillance, which is here the premise of a film which involves a seemingly innocent person, concealed both from ourselves and from the protagonist, controlling the events in a posh restaurant, so that a woman out on a date has been chosen, after she had previously killed her abusive husband out of self-defence (that, at least, is what we understand to have happened), to assassinate the man with whom she is having a meal. She is being besieged by text messages advising her on the next course of action, with the threat that if she doesn’t carry out their instructions her child will be murdered.

In the wrong hands, this could have been a poorly executed thriller which capitalizes on trauma and abusive relationships in order to destabilize a female character who is enjoying her first date since the end of her violent marriage, and who simply wants the best for her young son. But where this film works is in the way it upends the question of who is in control, and gives us a heroine who is far from a damsel in distress and who has the capacity to fight back against her assailant whose identity is only revealed in the last act.

The majority of the film is set in a single space, giving an aura of claustrophobia and tension to the events that follow in which Violet (Meghann Fahy) has to keep sabotaging her date because of the instructions she keeps receiving, and she has to resort to ingenious means to ensure that Henry (Brandon Sklenar) does not get too suspicious or annoyed and exit their date. Her and her son’s survival depends on the date from hell from persisting way beyond its use by date.

The technology is stopping them from really enjoying each other’s company, and ‘Drop’ is a skilful lesson in the way the very tool that can bring people together – after all, they are only on this date because they had met online – is also what drives a wedge between them. There are a few moments that confuse, as when the opening scene in which we see Violet being attacked by her ex looks like it might be a flash forward to the end of her evening with her date, rather than a flashback. And credibility is stretched by us being expected to imagine that the killer is privy to every hand movement, facial reaction and, we almost imagine, thought process, going on. But, this also functions effectively because we genuinely do not know who the culprit is and how much they know, so that only when we think back on the film afterwards do all the loose ends and misdirections seem implausible and exaggerated.