The Orient Express, 1923

Although possibly not a part of its original "type-in" published form there seem to be many versions out there (I used a GWBasic version for MS-DOS, which can be found on Web) that contain program errors that make the game unwinable. Some of the errors in the code, though, were put there on purpose by Ahl in a clever scheme to obscure the solution from those using the tried and true technique of reading the Basic source listing. The Basic code, in this respect, is part of the allure (and original purpose) of this game. It is well structured and and heavily commented so that aspiring Basic programmers could use it to learn how to program their own adventure games. However, beyond these pedagogical benefits, if you can find a version that has been debugged, and you like logical puzzles, I can highly recommend this game.

That being said, the logical puzzle at the heart of this game is absolutely diabolical. No simple truth tables will be adequate for this one, and Ahl's recommendation in the supporting documentation that an "hour or so" will be required to finish, actually seems somewhat optimistic. The adventure is structured along the lines of a game of Clue, but from my attempts at trying to figure it out, I would say that it is not simply a logical exercise. Some of the clues are, I think, red herrings. Others require knowledge of (or research into) European cultures in order to properly interpret (such as the elements that go into French cuisine and an understanding of the diversity that characterizes European cheeses). The game also has historical elements that are absent from a game of Clue and the use of some simple sounds and descriptive messages are highly effective in invoking the feel of a long train ride.

Also, this game is not a standard two word parser. Rather, single key strokes and options are all you get, and most of these, are largely irrelevant to the solving of the puzzle (although they help add to the atmosphere of the game). In fact, it is really just a clever and engaging way to reveal a long sequence of narrative clues, after which one must enter two selections (the defector and the murderer) that the computer then will judge as to whether you have deduced correctly.

As with many low K Basic IF games, the supporting written narrative material is essential to the full enjoyment of the game. Ahl provides a detailed history of the company behind the Orient Express. I think most of this material is now included in most of the online distributions of the program. If not, it might be worthwhile to obtain a copy of Ahl's book, which like the famous train, should be considered a classic from a bygone age.