From the introduction to the one-hour version:
This is the first in a series of demonstration scenarios meant to introduce new players to the fun of Call of Cthulhu gaming. The scenario is designed to take approximately 45 to 60 minutes in total—just long enough for a taster of the game.
Where necessary, specific examples of rules at various points in the story are referenced. . . . Advice on moving the story forward is also provided. The scenario is written to ensure that all players, no matter who is running the game, have a very consistent play experience.
While intended as a convention style taster game, you are free to use the story as a jumping off point for a longer game.
From the introduction to the extended version:
This is an extended version of our popular one-hour demo scenario, designed to introduce new players to the fun of Call of Cthulhu gaming. The scenario’s normal one-hour time limit has been removed and up to six-players can be accommodated to provide everyone with a taster of the game.