Someone is adding dirt to my garden!
The plot thickens!
Listen up, buttercup. This joke is based on the double meaning of the word "plot." The first meaning is a piece of land, like a garden plot. The second meaning is the sequence of events in a story. So, when someone says "the plot thickens," it's funny because it sounds like the dirt is getting thicker, but it also means the story is getting more interesting. This is funny because you are dumb.