Who Killed Harlowe Thrombey?

Who Killed Harlowe Thrombey? was the ninth title in the Choose Your Own Adventure series, authored by the range's creator Edward Packard and first published in 1981. Its premise is exactly what the title implies: millionaire Harlowe Thrombey (president of Thrombey Plastics Company) is scared that someone is out to murder him and hires you (despite the fact the text heavily implies you're still a teenager), but before he can explain things further, he is fatally poisoned, leaving you to interrogate the four suspects -- his wife Jane, nephew Chartwell, niece Angela, and Angela's fiancé Robert.

WKHT? contains a modest 122 pages, which includes full-page illustrations and sections which are spread over two pages, and yet it is a spectacularly successful example of a murder mystery done as a gamebook. The range very, very rarely tried to do a straightforward whodunnit after this one despite producing in excess of two hundred more books (and the ones they did do mostly appeared in the dying days of the range's original run in the mid-to-late 90s), and I wouldn't be at all surprised to learn that they felt they couldn't live up to this one. (Packard did write a sequel using the same player character, Ghost Hunter, but as the title suggests that book took a shift into the paranormal and saw you become an, er, ghost hunter, trying to track down the ghost of Harlowe Thrombey himself.)

The book is remarkably consistent and well-plotted, with every path having the same solution and absolutely no cases of contradicting itself at all. Some paths where you figure out who the murderer is end in your death because they kill you before you can expose them. Other unsuccessful paths give you a glimpse of the picture -- it's possible to capture one of the killers but not their accomplice and never learn of the guilt of the latter. Or you can dilly-dally for so long that someone else solves the mystery before you do. There is only one true, golden ending where you yourself solve the murder, track down everyone involved and tie up every loose end, even if it's possible for you to believe you've tied everything up by reaching another ending. The book really is a little miracle of engineering. And yes, Rian Johnson has confirmed that the name of the victim in Knives Out is not a coincidence.

I'm not sure, but I think this page might hold the record for "most outgoing options in a single section" for any gamebook. (As you can see, WKHT? is also a little unusual for a CYOA book in that some choices are only available depending on previous ones; here, you can only investigate certain pieces of evidence if you actually found them earlier.)

(Okay, okay: Technically there's more than one ending that could be considered optimal, as there is a character tangentially involved in the killing you can track down, and whose existence you are not even aware of in the other path. Whilst Packard may have considered meeting this character an added bonus, in the ending where he confesses you receive a cheque for $5,000 from one of the cleared suspects, perhaps indicating he deemed that the 'true' solution to the book.)

Perhaps my very favourite thing about the book, though, is Packard engaging in a minor bit of trolling. Several sections inform you that if you're absolutely certain you've solved the mystery, you should turn to page 122 -- which is also the very last page in the book. A page which reads, in its entirety: