The official description of the series via Valve reads: 

"The Peterson Case is an exciting horror game which will keep you on the edge of your seat – play as detective Franklin Reinhardt as you explore a deserted house; unravelling the spine-tingling tale of what has happened to its missing residents. Set in 1947, in a location near the Roswell UFO incident, you will play as a experienced detective who has been called in to find information and clues from around the Peterson’s home, to reveal what has happened to the mysteriously missing family. Franklin soon discovers that there is an unearthly presence within the house who is hot on his trail – but can he solve the crime before it is all too late? The Peterson Case strikes the perfect balance between atmospheric horror, suspenseful narrative, and engaging puzzles, taking the player through a unique experience which is rare within the horror genre."