Glazer and his co-writer Walter Campbell initially conceived the concept of the film as a high-budget flick that involved two aliens masquerading as a couple on earth. However, he altered the scope and focus of the film by centering on the female protagonist alone which would become the final script. Rather than create an elaborate sci-fi film he stripped the script to its core, thus, becoming a film about a lone alien creature experience on earth. A far departure from its source material that is much more explicit in nature. Hence the film’s ambiguous story which is also rather scant in regards to backstory and the alien’s intentions.
Glazer aimed to convey the film in a realistic manner, therefore, incorporated non-actors in supporting roles while filming guerrilla-style. For instance, he would choose to secretly film several scenes, particularly where the main character lures her men into her van. Then would later ask for approval from the participants on whether to use the material. Glazer’s intention for the plot was to portray the human experience of an extraterrestrial being feeling things for the first time. Hence the director incorporating music that encompassed the feelings of these experiences such as food and sex. Furthermore accentuating the natural sounds later in the film that the character encounters.
