Robinson takes on an arduous summer job with a road paving crew so that he can learn to operate the heavy equipment needed to excavate an oblong ditch just long and deep enough to contain the car, but not so wide as to allow escape through its doors.
On the night the plan is attempted, however, Robinson's trap works flawlessly, and Dolan's Cadillac drops into the pit as the altered section of road collapses under its weight.
Dolan attempts to reason, negotiate, and finally plead for his freedom, gradually becoming less coherent as the sound of dirt cascading over the Cadillac's roof erodes his sanity.
He manages to recover, never returning to roadwork, and a fortuitous sandstorm works to ensure that Dolan will remain hidden; his disappearance goes largely unmourned, and the press jokes that he is "playing dominos or shooting pool somewhere with Jimmy Hoffa."
Robinson muses that one day, the sinkhole created by the buried Cadillac will cause the road above it to collapse, risking its discovery; however, the specifications Dolan ordered to protect himself will ironically ensure that this will not occur for a long while, and it may even just be covered over again.
He notes that he occasionally drove along the same highway, and on the final occasion urinated on the spot where he believed Dolan was buried, but has since taken to driving an alternate route.