Jack sews up Kate's wound, their new goal is to kill Locke

On the beach, the sun is rising as Jack pulls some thread from a shirt to sew up Kate's bullet wound. He warns Kate that it's going to hurt, but it will keep the wound from getting infected. She wincing in pain as the needle goes in and he starts to work. Hurley and Sawyer can be seen sitting nearby.

As Jack works, Kate sadly says that Jin and Sun had a daughter whom Jin never got to meet. Then she switches from sad to angry as she says Locke killed them and they're going to have to kill Locke. Jack says "he knows."

It seems obvious that they need to find a way to kill Locke, but how do you do that? Sayid tried and failed and we've seen numerous times that guns don't work, so how can it be done?

Also, the scene of Jack stitching up Locke is reminiscent of the first episode of season 1 where Kate sews up Jack's wound. We seem to be coming full circle.