There is some sort of iconic status it seems to this 1982 Lodge we're about to meet. I enjoy, below, that Shadows of Yog Sothoth included clues and bits and pieces. If that feeling can be invoked on the cards that'd be cool.
The first book of Call of Cthulhu adventures was Shadows of Yog-Sothoth. In this work, the characters come upon a secret society's foul plot to destroy mankind, and pursue it first near to home and then in a series of exotic locations. This template was to be followed in many subsequent campaigns, including Fungi from Yuggoth (later known as Curse of Cthulhu and Day of the Beast), Spawn of Azathoth, and possibly the most highly acclaimed, Masks of Nyarlathotep.[3] Many of these seem closer in tone to the pulp adventures of Indiana Jones than H. P. Lovecraft, but they are nonetheless beloved by many gamers.
Shadows of Yog-Sothoth is important not only because it represents the first published addition to the boxed first edition of Call of Cthulhu, but because its format defined a new way of approaching a campaign of linked RPG scenarios involving actual clues for the would-be detectives amongst the players to follow and link in order to uncover the dastardly plots afoot. Its format has been used by every other campaign-length Call of Cthulhu publication.
The standard of the included 'clue' material varies from scenario to scenario, but reached its zenith in the original boxed versions of the Masks of Nyarlathotep and Horror on the Orient Express campaigns. Inside these one could find matchbooks and business cards apparently defaced by non-player characters, newspaper cuttings and (in the case of Orient Express) period passports to which players could attach their photographs, bringing a Live Action Role Playing feel to a tabletop game. Indeed, during the period that these supplements were produced, third party campaign publishers strove to emulate the quality of the additional materials, often offering separately-priced 'deluxe' clue packages for their campaigns.
Additional milieu were provided by Chaosium with the release of Dreamlands, a boxed supplement containing additional rules needed for playing within the Lovecraft Dreamlands, a large map and a scenario booklet, and Cthulhu By Gaslight, another boxed set which moved the action from the 1920s to the 1890s.