Yeah, that top layer is almost always the worst one to date from. Wind, rain, animals, even old farming can churn stuff up from deeper levels and drag it to the surface. You might find a colonial pipe stem sitting right on top of a thousand year old hearth stone. That's why we dig squares and screen everything, the real story is always deeper down.

Yeah, that slow fade anderson.cora mentioned really had me on edge too. Even when you know how it ends, that kind of drawn-out worry just gets to me every time.