ok, so the bacics of it was that Beetee was supposed to drive the knife through the chink in the wall. if he succeded the force field would have died and they would rescue them, but what happens, Beetee misses(i think and hits the force field full on.). Beetee had the timing wrong and i believe he was going to drive the knife in when the lighting struck the tree, overloading the feild and making it go kaboom! but that went wrong. Katniss eventully saw what he was trying to do, and shot an arrow into the field. why the arrow killed it and the knife didn't, thats easy, Beetee couldve hit the field at about 20MPH (32.186 kilometers an hour) but an arrow can go up to 85MPH(136.794 kilometer/hour) the field goes boom and the district 13 airship flies in and picks her up.

the twig was a basic version of a transformer, reducing the electricity to the survivable point , as it took the lighting, hand 1/2 go to the beach and knife and the other 1/2 going to the stick(probably incinerated the stick(Beetee needed it to be less electricity so he could survive the blast.).

^that makes sense

wow... thank you so much for explaining all the science and stuff behind that. that cleared you a lot!

^ That explains a lot!
(it actually does, no sarcasm)

Wait... you mentioned that the reason why it worked was because Katniss could hit the force field faster with the arrow, but I don't remember that being the case. Katniss could get it through the chink in the armor, and that's why it exploded. Correct me if I"m wrong.

^^ now that you mention it, does the chink in the armor acts as a hole or a weak spot able to explode.

That's what I thought. Just driving an arrow or knife into the force field won't do anything, no matter how fast. I"m pretty sure it's got to be the chink in the armor.

^^ well i thought she hit the chink but as i said. is the chink an actual hole or just a weak point in the force field?

I believe it's a hole... how else would Katniss get an arrow through it?

maybe she could slightly pierce it?