Today, I was feeling a little creative and compiled a small selection of Call of Cthulhu investigation seeds for your consideration and further development. I have purposely left these vague enough for you to take them and twist them into whatever suits your needs and game play style.
[Any time period] A child goes missing from the estate of Stephen Babbcock, a local politician and dignitary. The police have reported that there are positively no signs of a break-in and the house was locked up tight. What happened to their child?
[1920s or later] Mysterious lights are regularly sighted on a dark and winding local road by drivers in the middle of the night. What is the cause of the lights?
[1914-1945] A soldier has returned from the war and although he suffers no physical injuries, he is known to incoherently babble about dark and mysterious beings that would regularly assault him and his men in their trenches or foxholes. What are the beings and what did they do to them on the front lines?
[Any time period] Night time passersby regularly report chanting coming from a local burying ground. When the police investigate they are unable to locate anyone. The evidence always points to a dozen people having gathered around the grave of a woman who is reported to have been a witch during the Salem Witch Trials. Are these cultists? What are they attempting to do?
[Modern] A recent archaeological discovery coincides with the state of the art theft of a rare cuneiform tablet from a large and popular museum. What was the recent archaeological discovery? How does it connect to the heist and for what purpose?