Dannay and Lee remained circumspect about their writing methods. Novelist and critic H.R.F. Keating wrote, "How actually did they do it? Did they sit together and hammer the stuff out word by word? Did one write the dialogue and the other the narration? ... What eventually happened was that Fred Dannay, in principle, produced the plots, the clues, and what would have to be deduced from them as well as the outlines of the characters and Manfred Lee clothed it all in words. But it is unlikely to have been as clear cut as that."