One person we expect will be especially affected ishis BFF, Derek (Patrick Dempsey). But what will the effect be? Here are a few theories about how Mark’s departure might change Derek.
It might push him closer to his family. We expect to see Derek lean onMeredith (Ellen Pompeo) after the loss of his friend, and we wouldn't be surprised if he ends up spending a lot of extra time with Zola, too — especially if his hand injury keeps him out of the OR for a while.
Will it keep him in Seattle, or push him away? Perhaps losing Mark will convince Derek to stay in Seattle to bond with the few friends he has left. Plus, if Mark is gone, who will Derek sell the dream house to? On the other hand, Mark leaving might make Derek feel like he really has no reason to stay. We could see it going either way.