First of all, I really enjoyed this episode and give it 9.5/10 stars. However I just wished that it was longer and that they explained the Jacob's/MIB cabin ordeal. Now with that out of the way let's do the analysis. Circa between the year 3000 B.C. and 31 B.C. (the end of ancient Egypt.)This is evident in the fact that they(Adam and Jacob.) played the Egyptian game Senet. Crazy Mommy believed in Tabula Rasa (clean slate) and didn't want Jacob and Adam to the corrupted by the selfish deeds of man. Sure it may sound quite hypocritical on her part but it's therapeutic to her and they rid her of her solitude. Then comes in the Heart of the Island which one of them must protect from man who is greedy and can't get enough of it. Added to the fact that bathing in the water is "worse than dying." Then comes the manipulating of crazy mommy wanting to die by the hands of the MIB/Adam, ergo creating a conflict between Adam and Jacob. (Crazy (Mommy was never Smokey.) Conclusively Jacob throws Adam into the light and creates an anomaly (smokey) Heres Proof that the smoke monster got created in that same instant.
Personally, I think it was an amazing episode and it's up to the viewer to fill in the gaps and create an answer that satisfies them.