This book has benefited greatly from the encouragement and assistance of many people whose names do not appear on the title page.
First and foremost, my thanks go to Mathew Prichard and his wife Lucy. The very existence of this book is due to Mathew’s generosity. He unhesitatingly agreed to my writing about the Notebooks when I first approached him. And he not only granted me complete and unfettered access to all of his grandmother’s papers but he and Lucy also extended me limitless hospitality on the many occasions when I studied them.
David Brawn, HarperCollins, for his faith in the project and Steve Gove for his eagle-eyed editing.
My brother Brendan read an early draft and his positive words gave much encouragement; and with his wife, Virginia, he provided me with a home-from-home (but with superior technical backup!).
My friend and fellow Christie devotee, Tony Medawar, made many helpful suggestions as well as sharing his research with me.
Felicity Windmill, HarperCollins Archivist; Dr Christine Faunch and her staff in Exeter University Library; Tamsen Harward and Jemma Jones at Agatha Christie Ltd.
David Headley of Goldsboro Books for his invaluable help and advice.
My many colleagues and friends in Dublin City Council for their support, especially Michael Sands, Press Officer and Jane Alger, Divisional Librarian, Readers’ Services.
And, for various reasons, my thanks also to Eurion Brown, Pete Coleman, Julius Green, John Perry, John Ryan, John Timon, Andy Trott and Nigel Wollen.