When people talk about Luke Jennings's 'Villanelle' novellas and the 'Killing Eve' series, there's a bit of a sequencing puzzle because the books were re-packaged after the TV show blew up. The three books most commonly found now—'Codename Villanelle', 'No Tomorrow', and 'Die for Me'—are actually compilations of the original four e-novellas. For getting inside the characters' heads, especially Villanelle's, you have to start at the beginning. 'Codename Villanelle' is indispensable. It lays out her origin story in the foster system, that cold, surgical detachment, and her first kills in a way the TV show only hinted at. You see the world through her eyes: luxurious, amoral, and utterly bored until Eve Polastri becomes her obsession.
Eve's perspective is trickier. The books are far more focused on Villanelle; Eve often feels like the straight man to her chaotic energy. Her internal monologue in 'Codename Villanelle' is mostly professional frustration and mounting dread, which does give you a sense of her doggedness. But the real shift happens in 'No Tomorrow'. Their first real interaction, the famous kiss in the bathroom, is depicted with a rawness the show adapted differently. You get Eve's spiraling thoughts, the addiction beginning, and a clearer view of her crumbling marriage to Niko. It's less about spycraft and more about this compulsive, destructive attraction.
By 'Die for Me', the insight becomes almost claustrophobic. They're joined at the hip, and the POV shifts between them more frequently. You see Villanelle's rare moments of vulnerability, her confusion at wanting something she can't just take, and Eve's complete moral unraveling. The book's ending, which is much bleaker and more final than the TV series' third season, offers a stark character conclusion the show avoided. For pure, unfiltered access to their psyches, reading all three in order shows a complete arc from detached monster and curious agent to two halves of a single, doomed entity. The later books don't add much new dimension so much as they turn the screws on the dynamic established at the start.