i have not seen the episode it has not been air here yet. But my idea is that the J is from say around the 29th, 28th century and they have the large defector because of time travell. My final point is that i belive that both ships are from say 6 or 7 years after voyager arriving home. And are there investigating the temporal gate that the enterprise is genterating. And the reason for the movements of the enterprise is because of weapons discharge on the other side of the rift. Or i have any other plan but i cant be bother to explain now. I will if people dismiss this idea.