Historian Tom Mahon, with the aid of cryptologist and code breaker James J. Gillogly, has spent the past few years breaking the IRA's secret communications code, used to pass messages back and forth between Ireland and America from the 1920s until the 1930s - and the results are explosive. From discussions about matters to considerations of deals with the USSR and China, the IRA letters delve into just about every matter conceivable for a paramilitary organization. Some of the ideas are discussions about money and the likelihood of infiltration but others, like the proposal to source nerve gas for use in Ireland, are a dangerous and unnerving insight into how the organization saw itself and conducted its business. With the eye of a historian and the tools of a professional code breaker, Thomas Mahon and James J. Gillogly have together created a wonderful and engrossing read.