Joseph Morgan gives us a little more intel on possibilities of why Katherine has popped up again via TV Guide.
While the trio’s drama was playing out in Mystic Falls, a very big enemy of Klaus’ was returning out on the island. Just as Jeremy (Steven R. McQueen) was trying to get the cure free from Silas’ fossilized hands, Katherine swooped in, grabbed the cure, and was gone before Jeremy could breathe his final breath. What does this all mean for the hybrid who despises the doppelganger? “Well, there are going to be interesting developments with that,” Morgan says. “We’ve got to bear in mind this is someone who Klaus hunted down for 500 years. So she’s going to want to do everything she can to avoid him, whether that’s trying to kill him or make peace with him or trying to broker a deal with him, that remains to be seen, but absolutely not something that’s brushed over.”