Fackelmann's scam; the wraith returns (p. 926)
It had been Pamela Hoffman-Jeep that finally clued Gately in on the little ways Gene Fackelmann had been historically getting over on Whitey Sorkin, and alerted him to the suicidal creek Fackelmann had got himself into with a certain mistaken-bet scam that had blown up right in his map.
Context
Gately flicking the top of drunk, papoosed P.H.-J.'s skull to keep her conscious enough to free-associate the story out: O'Shay took Eighties Bill's $125K Yale–Brown bet backwards, both sides paid Fackelmann, and Fackelmann kept it all. "Blown up right in his map" runs the idiom's two senses at once — the scam detonating in his face, and the detonation being what will get his map eliminated. "Suicidal creek" keeps the book's suicide-vocabulary hovering over what is technically a murder plot: the scam as slow self-elimination.