fer pete's sake lol, don't focus on Jack and the girl, focus on the engine, there's a black streak flying down at the engine and it seems to make it explode. In the last episode you see this black smoky streak going through the jungle and you see strange faces in the smoke during the explosion when they save locke from whatever was dragging him. It's clear as clear in the video, actually there are two streaks, one directly above the engine, one flying at side. i hope I haven't spoiled it for anyone who hasn't watched the whole season yet.