Just resurrecting this thread given that tomorrow's episode has been
From the outset I've thought this storyline was being built towards either a double exit for the characters by way of a sunset ending or a tragedy for Harry.
Given that Harry has recovered from the accident and they've already done the whole 'I need to be alone to find myself' cliche with MC planning to go to the US alone several weeks ago, I am fairly sure that the final twist will be a sunset ending with them both leaving together. Maybe with a grand gesture from Harry??? There has still not really been any official word confirming that Niamh is definitely leaving but it seems almost certain now.
I will really miss both characters. Always liked MC and have really grown to like Harry through this storyline. I am hopeful they at least get the happy ending and that MC, at least, will re appear in future.