Reclusive mathematician Stephen Ezard returns to England to attend the funeral of his brother Michael, an aid worker killed by a landmine in Afghanistan. He finds a world that has changed subtly but significantly from the one he left and feels like an outsider. Bewildered and ill at ease, Stephen is pulled into a spiral of strange events. Can Stephen take control of his life and learn more about how Michael met his death?

Stephen continues his search for Yasim as two groups track his movements, T.I.A. marketing intensifies at Parliament, and an unexpected illegal debarks at the port.

Russell saves Yasim and Stephen against his better judgment, the government becomes suspicious of Stephen, an unexpected player joins the game.

Stephen deals with a rival for Yasim's affections and sudden homelessness after his identity is removed from the database.

As Stephen finally pieces together the conspiracy, Michael's illness worsens and another moves to tie up all the loose ends.