Aha, I have found something. A series of screenshots. I did not take them, I merely found and nicked them.
We had this computer game when I was a kid, called Hugo 2: Whodunit. It was the sequel to another game (which I never played until grade 12, at my then-boyfriend's house, during which I got vaguely annoyed at him and our other friend during the copy-protection trivia because goddammit, if I tell you the right answer is that you drink
a Pan-Galactic Gargle Blaster, I know what I'm talking about). Released in 1991, it's a parser-based DOS adventure game. It's... pretty hideous. And pretty merciless, too. It's very easy to die, and even easier to get yourself in a situation where you cannot beat the game.
The plot is such: You are Penelope, the girlfriend of Hugo. In the first game you needed to be rescued by terrible villains, but have now gone with Hugo on a holiday to a nonspecified place in England to visit relatives. And then Hugo disappears and you witness a murder, and you must, of course, solve it.
There is a sequence in the game which is, frankly, kind of insane, and it also terrified the crap out of me at the time. I was probably ten or eleven. The game was a few years old at the time.
After getting out of the house through a series of secret passages, and passing by deadly killer bees and navigating an extremely irritating maze, Penelope comes across a phone booth. She calls the police. They say, "Sure, well, we're busy right now, but if it's a murder, we'll be there at six. See you then!" Gee, thanks.
If you then dial a number you find written on a wall nearby, you get the following experience. This is not an easter egg. You have to do this to get a an object needed to win the game.( Are you ready? )