Best free DOS "mystery and detective" games

In mystery and detective video games, the player isn’t asked to run or fight but to watch closely, doubt what seems obvious, and piece together fragments of a hidden story. You often step into the shoes of a detective, a journalist, or simply an ordinary person caught in unusual circumstances, forced to gather evidence, question suspects, and decide who can be trusted. Atmosphere is everything: dim rooms, ambiguous clues, and characters who always seem to conceal something. Every breakthrough feels earned, never handed out, making the solution of a case not just progress in the game but a personal triumph.