Board Thread:Spoilers!/@comment-27060727-20160824022100/@comment-24674051-20161024040348

I doubt it. I'm betting something more along the line of hunting a Giant Squid. Perhaps Nemo has needs to get the squid for the same reason that Killian would want it, to get revenge on Rumple. However, Killian's desire for revenge (at that time) causes him to double cross Nemo, and causing both the to lose the opportunity to get their revenge. That will be the flashback (my guess).

Present day, will deal with the Killian's keeping of the shears, combined with probably moving the Rumple/Belle story line forward. There should be a bit of movement on the Charming storyline, but that will be secondary to the main story for the episode.