Is There a Time Traveler in the Cave?

I couldn't even recognize any of the characters in any of the scenes. I felt like there was stuff that was happening that was really momentous if you knew who these people were. But I just had no idea. How many seasons has it been going on for? Many more seasons than I've watched. Do you have to watch the whole show from season one to the forward or can you skip around? And if it's not going to make sense, might as well, right?