While Liet Kynes serves as an integral aid to Lady Jessica and Paul's survival in the ruthless climate of the Arrakis deserts by providing them with necessary tools, she herself bites the dust not long after that. While the movie lays out a cinematic scenario for Kynes's untimely death, the book paints a different picture.
In the movie, while surrounded by Harkonnen warriors poised to kill her, she bravely summons a sandworm by pounding on the ground, which then comes and engulfs her along with the Harkonnens. In the book, however, she's left to fend for herself in the harsh Arrakis desert without so much as a stillsuit or water for survival. She ultimately dies from exhaustion, dehydration, and delirium while in the throes of a spice blow.