In loads of old westerns, the sheriff would ask you to leave your guns at the door - well, this requires you to do that with your brain. If you try to study it in any sort of detail, then the plot holes will sing far more loudly than Aretha Franklin (or Jennifer Hudson) could ever hope to do. If you do, though, then it is quite an efficient little shoot-em up that sees wily old Gerard Butler ("Viddick") and his prey "Murretto" (Frank Grillo) engaged in a life or death siege inside a police station with only the rookie "Valerie" (Alexis Louder) and an armour plated door between them and the mad... read the rest.