Fackelmann, Sunshine, the beach (p. 980)
The word on the C-II Talwin-PX was it was intense but short-acting, and pricey. No word on its interaction with massive residual amounts of I.V.-Dilaudid. Gately tried to figure while he still could. If they were going to eliminate his map with an O.D. they’d have used something cheap. And if the librarian was going to sew his eyes open. Gately was trying to think. Too they wouldn’t have got him. Him. Got him off.
Context
The novel's final scene. Bobby C's crew has just needled Gately with pharm-grade Sunshine in the wrecked luxury apartment, Fackelmann's eyes are being sewn open a few feet away, and this is Gately's last piece of reasoning before the Sunshine crosses the barrier — sums done entirely in the idiom: if the plan were to eliminate his map, they'd have used something cheap. The eliminate-your-map thread gets its final occurrence in the book's closing pages, inside the head of the man going under.