Overall, this is more of a straight mystery adventure without as many potentially supernatural occurrences (or even the perception of such), as most Doc novels. The real mystery throughout most of the book is, “What exactly is Spook Hole?” What is it? Where is it? Why are so many people interested enough to kill for it?
All but one of Doc’s crew makes an appearance in this one (another indicator of it falling in the first half of the series). Even Doc’s cousin Pat Savage gets in on the action, as if you could keep her out of the fray once she’s gotten a whiff of an adventure to be had. One of Doc’s aides spends most of the novel undercover, but I won’t spoil that by naming names.
The novel spends a bit too much time spinning its wheels in the first half, with various individuals or groups chasing after one another and trying to avoid Doc and friends. This is still fun reading because a lot of “Docisms” are on display such as various disguises, infiltrations, 86th floor lab break-ins, Monk/Ham insults, the upstate criminal college, and gadgets galore. However, it fails to advance the plot much. When we finally get around to Spook Hole, the plot develops nicely, and the guest character build-ups pay off. The final McGuffin reveal was a little under par but that’s OK. These books aren’t really about that anyway. The story does feature one of my favorite character names in the entire Doc Savage series: Hezemiah Law. Whether or not he is a good guy or a bad guy…well, you’ll have to read the book to find out.