Jake Gyllenhaal once again proves how good of an actor he is, especially a character actor. He plays this role, Joe Baylor, a 911 phone operator with such intensity has he battles inner struggles alongside the torment of an abduction. For me the film isn't as entertaining as it is without Gyllenhaal in the lead role. Others may disagree but this reminded me slightly of his performance in 'Prisoners' in which he plays a detective battling similar demons.
I really enjoy films that take place in one location as it immerses you more into the narrative and I think director Antoine Fuqua (Training Day, The Equalizer) does a very good job in keeping the tension centred around Gyllenhaal's character.
I don't think the writing is anything spectacular, it's really Jake Gyllenhaal's performance as well as some stellar voice acting via the phone calls that carry the film.
It's an enjoyable watch that I had a good time, albeit it wasn't a great film, but it had a great performance from a great actor.
Great.