"He was a lot of things to me" "The only conclusion was love"
I could see the Lost Boys maybe kidnapping Henry when they find out their leader, Peter Pan, betrayed them by growing up. Maybe their revenge is to steal away Peter’s son in the hope of making Henry their new leader.
I could see that too, but I think it would have to happen after they were in Neverland. Can the Lost boys travel like Peter? I have this idea that only Peter Pan could fly between worlds, not the Lost Boys. So for some reason the family (which is basically the entire cast at this point) ends up in Neverland and then the first half of the season or so is spent trying to find a kindnapped Henry.