In January, Madame Arnulfi marries Druot, who is promoted to master perfumer and glover, although the Madame keeps her name and control of the finances. In March, Grenouille decides to see how the mysterious girl's scent is developing. He's overwhelmed by the scent when he catches it, and again stands outside the garden wall. Rather than being intoxicated, Grenouille is happy like a lover. He doesn't love the girl herself, just her scent, but he swears that he'll bring home her scent within the year.
This passage again draws the reader in while simultaneously repelling them. Grenouille almost elicits sympathy and compassion here, although the reader knows that he doesn't love the girl in a conventional sense. His desire for her is entirely possessive, and it’s likely that she'll be murdered soon, making this passage infinitely more disturbing.
That night in his cabin, Grenouille thinks of the girl's scent and immerses himself in it. When he begins to fall asleep, however, the scent disappears and Grenouille is terrified. He wonders what will happen when he runs out of the scent, thinking he'll have to live with the knowledge that he had at one time possessed the perfume. He wonders what he needs the perfume for at all.
This moment of questioning mirrors Grenouille's discovery that he has no scent in its scope and effect on Grenouille's goals and reasoning. We see that he's gaining self awareness here as he questions his reasoning for even following through with these goals.
At that thought, Grenouille feels chilled and wonders how long he can keep the scent. He wants to walk out and make the trek to his old cave, where he could fall asleep and die, but he resists the desire, as it's a “known” desire. Possessing and then losing a scent, however, is unknown, and he reasons that it seems more desirable. Grenouille "the tick," having reasoned to let himself drop one last time, lays back and thinks himself heroic.
Grenouille is overwhelmingly self-absorbed to think of himself as a hero for considering letting go of this scent. For Grenouille, though, the idea is like a religious sacrifice.
Grenouille continues his line of reasoning and considers how to make the perfume of the girl last longer. He finally sees that using the scent in pure form is crude and unsophisticated, and decides he must "set it like the most precious gemstone" in a setting of other scents, and for this he needs other ingredients.
The juxtaposition of the language of beautiful jewelry and scent with Grenouille's desire for these female scents adds to the horror at his plan. It also foreshadows his next moves to obtain "other ingredients."