2) These visions…
Dreams and visions are a strong and re-occurring element in the Lovecraft Mythos (which Chthonian Highways is rooted in). Characters often experience vivid, nightmarish and haunting dreams that are either the start of or a the consequence of their investigation into things Men Was Not Meant To Know. In Chthonian Highways such dreams are referred to as well, and the game-world is not offering its inhabitants the option to turn a blind eye to what is going on as those things force themselves upon mankind.
A GM who has a vision himself, so to speak, about what kind of shocking revelation he or she wants to be the peak of a campaign or series of sessions can construct a whole story around it and hook the player characters in by letting them glimpse places and events in their dreams. Of course, a GM is well advised to talk to the players first about if they would like to play characters that will sooner or later embark on such a journey or not, as nothing will be more frustraiting for everybody involved than a GM that has a journey up his sleeve which the player characters will avoid at any cost.
“Revelation” is the name of the game here. The GM should drop small puzzle pieces at the start which should include something mysterious, baleful or both. The characters will need to have a motivation to go out of their way and step out of the routine of their post-apocalyptic lives if they are to answer the call, and that motivation must be found in the call itself. Aside from the foreboding threat (which is a mainstay of many a RPG adventure), the personal link is a strong motivator. If characters see themselves in their dreams, doing certain things and encountering certain people or objects, the characters might very well be motivated to investigate if these items, events or people are encountered by them outside of those dreams.
These kind of games must have a strong mystery element to them, as the players must be kept guessing as well as the characters. Some, but not all, of the turning points and events should be provided in dreams, and these dreams could and should be expanded as the story progresses. An important question comes to the role of “destiny” here: while fiction often features characters that have been forgone to take certain actions, the PC should have a free will and the possibility to act contrary to the visions they had, so the circumstances might very well encourage the outcome of the visions and/or punish the contrary. Especially the combination of both is a valuable tool as next to all players enjoy a moral dilemma, especially if they have the feel that they are pivotal for the further happenings in the game-world.
The game mechanics of “Torques” and “Troubles” of CH lend themselves to this kind of game very well, too. Whenever “Troubles” are rolled, the GM should feel free to make a bad or nightmarish part of a vision a character had about the situation come true (or: have it furthered). This will add an element of “fighting against the clock” to the game as it is unavoidable to role a “1” sooner or later while taking actions. The fate the eldritch powers have woven might proof unavoidable, too.
Last but not least, the end of the game should have a dramatic revelation… but shall not end with it. The final should be about what the characters do in regard to it, if they try to change it, try to run from it or give in. But it should never just stop with the vision coming true, unless the GM knows that the players like this somewhat fatalistic approach to drama.