"Dark They Were" is a short story written by Ray Bradbury. In this story we are introduced to a group of Americans who were selected to be sent to Mars and colonize the planet, while the USA is participating in a war. These Americans then store seeds, food, water, clothing, and other elements that will allow them to establish the colony on Mars.
The Bittering family was selected to be one of the settlers of Mars and soon after arriving they start to plant agricultural crops in the soil of Mars, as well as the other families. However, crops begin to behave strangely and do not look like the food on earth. Animals also begin to undergo strange mutations and even people begin to have their bodies modified, losing their human appearance and looking more like a Martian. Even the Bittering family goes through these mutations.
The colony completely loses contact with the American government and is unable to get help for their problems. However, at the moment when American astronauts manage to reestablish this contact and go to the Martian colony to check on how the colonists are doing, they do not find any human being, just a group of strange-looking but sympathetic aliens who speak English in an admirable way.
