At the Royaumont meeting, Pauling talked with a group about solving DNA the way he had solved the alpha helix: using precise x-ray work to confirm the structure of its building blocks, as Corey and his coworkers had done with amino acids. Do the nucleotides first, he said. Nail down the precise form of the bases and their relationship to the sugars and phosphates, then make a model of the most chemically probable long-chain structure that they would form. Jim Watson was there. And he paid close attention.

But when Pauling returned to Caltech in September 1952, he continued to work almost exclusively on proteins. "The field of protein structure is in a very exciting stage now," he wrote. "I have a hard time to keep from spending all of my time on this problem, with the neglect of other things."

That same fall, Pauling's son Peter arrived in Cambridge to work as a graduate student in Kendrew's laboratory. Peter Pauling, twenty-one, breezy, fun loving, more interested in the structure of Perutz's Danish au pair girl, than in the structure of proteins - "slightly wild," according to Crick - immediately fell in with Crick and Watson and their new office mate, Jerry Donohue, another Caltech expatriate who arrived on a Guggenheim after working for years with Pauling. Peter Pauling and Donohue were both in correspondence with Pauling and he with them. Their office talk provided Crick and Watson with at least a small idea of what Pauling was up to, and their letters provided the same service in reverse to Pauling.

It was becoming clear that others were in the race for DNA.