Despite the lack of action perhaps expected from the genre, this is the story of Smiley patiently and methodically untying a knot of deception thread by thread and contact by contact. It's dense, as le Carre throws the reader into an existing web of history, deception, and relationships which are initially half explained at best. It's a book that very much leaves the reader to pick up the pieces and make connections as they go along through context. Presumably this either works for a reader or they bounce off it hard so I could see it not being for everyone, personally I find this style of writing and le Carré's prose in general to be magnetic, making for an interesting and engrossing read as each new revelation comes to light.