In my search for mysteries that are neither grim nor silly, I've been exploring authors and books from the early 20th Century. The Red Thumb Mark is the first book in a megapack I picked up out of curiosity - though given that it's apparently close to eight thousand pages, I suspect I won't read it all!

The story was competently told. The prose was stilted in places, but not unbearably so. I did occasionally find myself impatient with the repetitions. The "whodunnit" part of the plot was straightforward, and I suppose the interest is more about the "howdunnit." Jervis as narrator felt more obtuse than he needed to be. The romance was shoehorned in and had me rolling my eyes. The forensic methodology explanations were quite interesting (I once studied Forensic Medicine), especially from a vantage of 100 years later. However, the villain's actions were unrealistic and were presumably contrived in order that Thorndyke could show off his acumen. That is, the plot was nothing special and served to showcase examples of scientific cleverness.