The is the very first Nancy Drew book I ever read, and I'm finally going to compare it to the original.
It starts out very different from the original, which opened up with Nancy and Mr. Drew talking about the greedy Tophams and the Crowley will dispute. In this, Nancy saves a little girl, Judy, who's run into traffic and then fallen off a bridge (she doesn't appear in the original). The Turner sisters from the 1930 text are back, but are Judy's aunts.
Nancy's introduction to the Hoover girls starts with Nancy nearly running over Allison Hoover as Nancy drives into the barn to take shelter from the storm. The Hoover girls' storyline remains much the same as in the original 'Clock' except that Allison wants to take singing lessons instead of growing a chicken farm.
Abigail Rowen gets a little more "screen time" here after she furnishes the most important clues of the case to Nancy. From that point the story basically follows the original, but is faster in pace. Jeff Tucker, the groundskeeper for the Topham cottage where Nancy finds herself locked up, is no longer a minstrel-show-type black man, but a generic elderly man. The story concludes as it did in the original, with some minor changes to the Crowley will.