Reading this after having read Tinker, Tailor, Soldier, Spy is like reading a fanfiction for a book I loved. The main character is the same--maybe more thoroughly explained and explored--the style is similar, though not quite as crisp, and the mystery is there. From the beginning it comes clear who the murderer really is, or is expected to be and just like Agatha Christie le Carré distracts the reader from the obvious masterfully. Their styles are different, but the method is the same. Misdirection and withholding of information. I liked it, but it wasn't the same as Tinker, Tailor.