In the six years since the second edition of this text, I have worked with many brilliant digital investigators and I have taught hundreds of students. Together we tackled sophisticated network intrusions and complex forensic investigations that stretched us mentally and physically, taking over our lives for a time. I am deeply grateful to each of you for your friendship and influence, and I would like to give special thanks to the following. The contributors Susan Brenner, Christopher Daywalt, Monique Mattei Ferraro, Bert-Jaap Koops, Terrance Maguire, Mike McGrath, Tessa Robinson, Bradley Schatz, Ben Turnbull, and Brent Turvey, for your inspiration and persistence. My entire family, for your support and patience. Genevieve, Roisin, and Hesper are my lifeblood, reminding me what is important in life and lifting me with limitless love every day. Ita O’Connor made all this possible, loving me unconditionally, teaching me right from wrong and how to write, and providing regular encouragement and editing during this revision. Clare O’Connor is my beacon and buttress, giving me guidance, love, and support throughout my life. Jim Casey, for your sage advice. Mary Allen Macneil, for your love and pride. H. Morrow Long and everyone else at Yale University, who fostered my early interests in incident response and who continue to support my endeavors. Robert Dunne, for his contribution to the previous edition; I mourn his passing.