The year is 19XX. The type of 19XX that has typewriters and fog and drinking in the office, specifically. Hero is off working on a secret case, so you have been given the role of substitute detective. Hero's detective agency isn't very popular, you spend most of your time just sitting around and chatting with Basil, your assistant. Until one day, a routine case turns out to be more serious than anyone could have imagined. With Hero nowhere to be found, it's up to you to solve it.
This is pretty silly stuff, though not quite as silly as Feral Basil. While that could maybe be classified as a sex comedy, this is more a comedy mystery. So expect silliness, but not nonstop silliness. Also, there's some violence, but nothing too bad, and some sexual references.
It should also be noted that there might be some weirdness if you try to play this CYOA on very small screen, like on a phone, so keep that in mind! It will still work, but the formatting might be messed up.