Original sentence: Only in recent episodes has their relationship come to the forefront of the storyline once more, in the form of Derek's planned proposal.The season has, up to this point, focused very little on the Meredith-Derek relationship - at least in comparison to seasons past
Edited sentence: Only in later episodes did their relationship come to the forefront of the storyline once more, in the form of Derek's planned proposal.The 5th season, for the most part, focused very little on the Meredith-Derek relationship - at least in comparison to seasons past