Soon after being approached by the IRA to re-join he returned to Tralee from London, where he arranged a clandestine meeting with an officer of the Garda Special Branch in a local cemetery, at which O'Callaghan expressed his willingness to work with it to subvert the IRA from within. At this point, O'Callaghan was still opposed to working with the British Government. A few weeks later, O'Callaghan made contact with Kerry IRA leader Martin Ferris and attended his first IRA meeting since 1975. Immediately afterwards, he telephoned his Garda contact and said, "We're in". According to O'Callaghan, "Over the next few months plans to carry out various armed robberies were put together by the local IRA. It was relatively easy for me to foil these attempts; an occasional Garda car or roadblock at the 'wrong time'; the routine arrest of Ferris or myself; or simple 'bad planning', such as a car arriving late – a whole series of random stratagems".