Just finished reading it and really enjoyed it. Kept me guessing until the end. However, one thing confuses me..
Tate only gave Kya the red hat towards the end of 1969 so he would have known the fibres couldn't have got on the clothes years before so he must have had a suspicion but at the end when he finds the hidden box and poems, it seems that he is shocked. Have I missed something? It doesn't add up.