intricacy         
noun uk/ˈɪn.trɪ.kə.si/ us/ˈɪn.trə.kə.si/
intricacies [ plural ] 错综复杂的细节
complicated details
  I enjoyed the film, but I couldn't follow all the intricacies of the plot. 我喜欢这部电影,但情节中有些复杂的细节我弄不明白。 
 She was well versed in the intricacies of the Homeland Security Act.
 He studied Mahler's scores to get a better understanding of the intricacies of orchestration.
 He grasped the intricacies of the financial system better than any of us.
 They lacked any understanding of the intricacies of modern warfare.
  [ U ]错综复杂 
the quality of having a lot of complicated small parts or details
  the intricacy of the needlework 针线活的复杂精细