Arrow Season 5: 10 Things You Need To Know
3. We'll Discover What The Promise Was (And It'll Have A Lasting Impact)
During Laurel Lance's death scene, she makes Oliver promise her something. We don't know what it is - there were even theories it would be about faking her death - but we are going to find out in Season 5.
That's good news, as it means a key part of Laurel's death will actually be important, and also answer one of the mysteries leftover from Season 4. The editing of the trailer for Season 5 makes it seem like the promise was for Oliver to not go it alone, which is the sort of thing she'd ask of him, and something he looks like keeping.
Adding a little bit more intrigue, however, is showrunner Wendy Mericle's response to the question of whether it'll be something to do or something not to do, telling TV Line: "It is both actually, and you’ll find out what it was in [the Season 5 premiere],” and adding it will “inform a lot of Season 5.”