The scientists race against time to analyze the Andromeda Strain. They review the computer’s spectrometry and the amino acid data. The results suggest that the Andromeda Strain is “an entirely alien organism” unlike any lifeform on Earth (141).

Stone studies a sample of the green patch using an electron microscope. He notices a perfect hexagonal arrangement, noting that the precision and accuracy of its structure seems too perfect for a living organism. He tells Leavitt that he believes the Andromeda Strain to be a kind of living crystal. Leavitt suddenly remembers his dream. He explains his idea to Stone, wondering whether they are only seeing a small part of a larger, more complicated organism. They talk about the Messenger Theory, a hypothesis that argues a sufficiently advanced alien culture might wish to announce its existence to the world using biological means like a self-replicating organism. Billions of these organisms could be sent out into the universe, and they would then grow into a fully communicable being on contact with another species. The scientists wonder whether their sample is developing into “some kind of organ of communication” (145).

Hall talks to Peter Jackson again. He encourages Jackson to talk about the night of the incident, but the old man is reluctant to do so.