"Our cast are all completely different and there's been a terrific chemistry between them," he adds, enthusing over McShane, back on the West End stage after a 30-year absence, and his multi-talented witches, Joanna Riding, Maria Friedman and American Lucie Arnaz. Nor has he anything but praise for the two American creators of the show, lyricist and book writer John Dempsey and composer Dana P Rowe, who had so impressed him with their show, The Fix.