REVISED 07-19-13: I had been hoping that this complete series would someday become available as an ebook in the Kindle store, and now it finally has, all 6 books (4 novels and 2 collections of short stories) bundled together in one collection. (I had read and enjoyed several of the titles that constitute this series a good many years ago, and I now look forward to finally reading the rest.)
Just to clear up two areas of possible confusion: FIRST, "The Four Just Men" is the title of ONE book that was later followed by FIVE others (for total of SIX), all of which became known collectively under that umbrella title. Technically, a complete "Four Just Men" could refer to the full, unabridged text of just that one, first book--but here it refers to a complete COLLECTION of ALL of them. SECOND, the publisher (Wordsworth) includes this title in its "Tales of Mystery and the Supernatural" SERIES, an umbrella term to include books that are mysteries OR supernatural (and occasionally both). This collection falls under the "mystery" category; it is NOT in any way supernatural.
When I purchased this Wordsworth edition (for $2.68, though the price has since risen), it was the only truly complete set available in the Kindle Store. There was briefly another set with all six books published by Pulptastic called "Complete Just Men Stories," but it has since been removed. Jame-Books offers an Edgar Wallace bundle of 25 books titled "The Four Just Men, and Other Stories;" while it includes these, the formatting (annoyingly large spaces between paragraphs in some books, but no paragraph distinction whatsoever in others) is not to my liking. It also has a TOC issue (as in the last two titles disappearing from it). I purchased the Jame-Books edition but, unhappy with its flaws, returned it for a refund.
Although this Wordsworth edition lacks a TOC, you can easily right/left click (on a Kindle Keyboard) to every one of the 6 titles (then bookmark each for future, direct acess); right/left clicking also leads to specific chapters within each book. (On the Kindle Paperwhite, tapping GO TO provides a list of titles; then, for a particular book, an additional tap lists chapters or stories within it.) This edition also has an informative introduction. At present this is the ONLY truly complete set specifically devoted to the Just Men series; be wary of numerous other so-called "complete" sets which do NOT contain ALL six books.
Trying to acquire all six of these books separately can be both challenging and confusing since U.S. titles frequently differ from the British. That's why a bundle for this series is particularly convenient; it's all done for you. I highly recommend this ebook edition to any discerning reader in search of some good, old-fashioned, British crime drama.
FYI: Edgar Wallace was a prolific author of "thrillers" and was VERY popular in the early decades of the 1900's. The first volume of this series was written in 1905; it was also the very first of some 170+ books he eventually wrote. Inasmuch as the last volume in this series was published (in Britain) in 1928, and he died in 1932, this particular series pretty much spans his entire writing career. Many of his other books are available in the Kindle Store (more than a few as public domain freebies), and the ones I have read thus far were quite good.