Martin Barrett is a retired design engineer living in the small New Zealand old gold mining town of Arrowtown in Central Otago. Raised and educated in London, he and his wife have traveled throughout France for many years. Interest in the 13th century Cathar heretics of Montségur, in south-west France, and their treasure and relic has taken him on two research trips to Cathar stronghold. 

   Motivation for The Heretic's Revenge was twofold. Could the Cathar treasure be found today, and what might it turn out to be? And secondly a complete account of the siege of Montségur and the 20th-century involvement of Otto Rahn, just needed to be told.

   Martin hates books with excessive padding and storylines that are implausible and has strived to avoid this. He enjoys skiing, biking, and walking in the mountains surrounding Arrowtown.