*The Puzzling Adventures of Doctor Ecco* is, at heart, a book of puzzles. Its twist is that instead of just stating the puzzles, Shasha has embedded them into a frame story about the rise to fame of Dr. Ecco, an eccentric but brilliant puzzle solver, as told by his good friend Professor Scarlet (it’s clear from the frame story that Shasha is fond of Sherlock Holmes). Each puzzle is presented to the reader by way of a client presenting it to Ecco. Questions for the reader to solve are written in italics, and set out from the rest of the text with a picture of a magnifying glass. The solutions are glossed over in the text, and can be found in the back of the book.

The puzzles are given rough difficulty ratings in the table of contents. This is great, although many of the puzzles have multiple parts and it’s not always clear how each part contributes to the rating. Puzzles of all difficulty levels are interspersed throughout the book, which seems like a good choice for a puzzle book that is meant to be read from start to finish. None of the puzzles require any specialized knowledge to complete, and a nice variety of types of puzzles are included, with enough repetition of general puzzle styles for the reader to be able to apply tricks from earlier puzzles to some of the later ones.

The solutions are well written. Some solutions have a discussion section, which generally points out a connection between the ideas used in the solution and some topic or idea from computer science or mathematics and provide a reference. The references themselves are almost certainly outdated at this point since the book was originally published in 1988 (this is especially true for the computer science references!), but they’re still a nice touch, and at least point the interested reader in the right direction for finding more information.

Although most of the puzzles or similar ones likely appear elsewhere, they are clearly stated here, and accompanied by well written solutions. This, plus the nice variety of puzzle type and difficulty, makes it a good source of activities for math club meetings or similar events. I brought several of these puzzles to one of our recent math club events, and both the students and other faculty enjoyed working on them. This is the first in a series of five puzzle books by Shasha using Dr. Ecco as a theme, and I enjoyed it enough that I might look into the others.

Megan Patnott is an Assistant Professor of Mathematics at Regis University in Denver, CO. Her training is in algebraic geometry and commutative algebra.