u/Educational-Ad3669

I just finished the 3 body problem and am beginning the second book but I’m so confused. I get that a Sophon is a folded proton or whatever but are they already on earth, or are they what is heading towards earth w the countdown? Also are they how the Trisolarians communicate? And if so then wtf is the countdown for? I’m just so lost and it’s making the book impossible to understand.