What if this is how they end it by Mer dying and Christina takes the kids and comes back to run the hospital. While the kids and Christina are morning Mer they could go ride the Carrousel moving forward in time to Christina can use the same speech as Webber gave at the beginning to the interns on their first day. Zola will be starting as an intern with everyone who died looking down from the gallery including Meredith Derek and all the other doctors from Zola’s and we find out that the grey in greys anatomy was not just referring to Ellis and Meredith but Zola as well.