This is the third edition of the Pool Re Terrorism Frequency Report and the last in 2018. We examine whether the threat of returning foreign fighters is greater than that posed by Islamist extremists who have not been to the so-called Caliphate (including the challenge presented by the large numbers of those now being released from prison). Also, the Security Team at Canary Wharf share with us the lessons they have learned from the five attacks that took place in 2017 and how they are preparing for the long-term security challenges. Our next report will be our annual Terrorism Threat and Mitigation Report which we will publish in late October. The annual report will review events over the last 12 months and, for the first time, will include detailed statistical analysis of terrorism data over the last four and a half years. We hope that, in time, this will facilitate an analysis of frequency which will in turn enable better pricing of terrorism products.