It is not good for a business of a PI to have his clients murdered shortly after they leave his office. Not only does it bring bad reputation, but it is also very damaging to self-esteem, something Nero Wolfe values highly. Thus this time it is personal. The detective who charges such high fees that only millionaires can afford his services most of the time now only has $4.30 to show for his troubles with not a single penny more on the horizon. It still does not matter as the reputation is at stake.
It was one of the first Nero Wolfe books I read and as such I might rate it a little higher than the usual, but not by much. It is a rare treat to see Nero Wolfe working for no fee and on a personal case. This time it really happens and this is the time the villain was repulsive for me I really wished he/she would get exactly what he/she deserved, and because the greatest New York detective was on the case there was no doubt about the outcome.
Archie Goodwin got to play quite a big part in the investigation acting on his own. His parts of the book feel like thriller unlike cozy mystery always associated with his boss Nero Wolfe.
The final rating would be closer to 4.5 stars, but as I already mentioned I round it up for sentimental reasons.