Overall I give this episode an "Excellent"
So, everything that happened, happened, BUT, there can be variables and they are the variables since they have traveled in time. Therefore, things CAN change! I find that very fascinating, and changes everything.
I loved learning about what the Incident is. Basically, a release of electromagnetic energy due to their drilling in that spot. Apparently it causes a catastrophe and similar to Chernobyl they have to cement it in and use a computer to release the energy so it doesn't build up. I love that. It is also my theory that The Incident might be the cause for why babies can't be born on the Island now.
So Penny and Daniel are siblings, and Daniel never got to know that, how sad, now he's dead probably (unless he comes back in ghost form which is possible.)
His mother sent him to his death, she knew she would shoot him, again pretty sad. Widmore is his daddy, very cool.
I was hoping Chang would believe Daniel was from the future, and I was hoping Miles would confess he was his son. That could have been a very interesting dynamic to explore there with Chang knowing.
Can't wait until next week!