Reeling from events in Barcelona, the reformed Mysterium circus company pack up and head for a new circus in Berlin. For twelve-year-old Danny Woo it is a date with destiny: it was in Berlin ('the city of escapes') that the last Mysterium performance took place, and where his parents perished in the mysterious fire for which Danny has been desperate to find an explanation.
Danny is closing in on Centre - the traitor who is either part of the Mysterium, or linked to it. But a vital last clue, left in code by Danny's father, is missing. And a dark figure is shadowing the convoy as it makes its way across Europe.
As the Mysterium pitches camp in Berlin, the snow begins to fall once more. The truth is within reach - but will Danny discover it in time enough to save not only himself but Sing-Sing - the sister he never knew he had.