This is the fourth and final book in Robertson’s “Carson Street Detective Agency” series, published in hardcover in 1969 and in paperback in 1971. It’s the easiest and cheapest to find as a used book, though the entire series is long out of print. The Agency is two teenage boys, Neil Lambert and Swede Larsen, and Carson Street has the loft over Neil’s garage where they have their headquarters in a small west central New Jersey town south of Princeton.
The book begins with a device Neil buys by mail from a magic tricks catalog that gives the appearance that it can print real money from a blank piece of paper. Actually, the real money has to be hidden inside first. Their use of the trick on friends leads to a visit from a Secret Service agent who is investigating a real counterfeiting case in the area. Before long the two boys are deeply involved in helping solve the case, making friends with an old man who used to be an engraver, and staking out the home of a likely suspect with the help of a new friend, Myrtle Cavanaugh, who happens to live next to the stakeout. Myrtle is a stamp collector who helps by spotting another case of counterfeiting, this time some old stamps, and she’s also a quirky songwriter who pens tunes about Neil and Swede. As usual, the boys get into tough fixes, like being trapped in the basement of the stakeout house, and their adventures and the mystery are told with humor and thrilling action.
Think of these books as The Hardy Boys but written with considerably more skill and talent. It’s a shame they haven’t been reprinted (the first book is impossible to find), but if you want to try one, this is the easiest to get. Recommended.