"The Great Old Ones" consists of a set of six scenarios for Call of Cthulhu: "The Spawn" is in the Wild West, with Indians, Wobblies, and bad guys; "Still Waters" is an adventure for people who hate to lend books; "Tell Me, Have You Seen the Yellow Sign?" makes a symbolic stop-over in New Orleans; "One In Darkness" features South Boston hoodlums; "The Pale God" introduces investigators to an unusual contract; "Bad Moon Rising" is an experience to remember. The adventures can be presented in sequence, as a loose campaign; limited cross-references allow the scenarios to stand independently.
Mostly decent adventures, however, the final one, though interesing, seems far too railroady to use. Also, while the adventures are presented as though they could be linked, those linkages are mostly tenuous, at best.