Crick and Watson believed that they had made real progress toward a major discovery about the nature of life and heredity. Despite his aloof personality, Wilkins clearly took Crick and Watson seriously—otherwise, he wouldn’t have visited. Still, Crick and Watson’s model was purely theoretical, and they knew they needed some experimental data to back it up. Thus, despite all their ill will toward her, Rosalind Franklin would actually prove essential to their work.