There are three stories here, all interlinked - but only at the start and only tangentially at that, that ask questions of humanity and loyalty amidst the sometimes quite brutal, lustful and occasionally humorous environments of a Mexico City inhabited by rich and poor alike. The opener follows the life of “Octavio” (Gael García Bernal) who lives with his mother, brother and his wife “Susana” (Vanessa Bauche) - for…