They are coming.
The "they," of course, are the time-traveling Observers who have taken over the Earth in the final season of Fringe. The fifth season takes place in 2036, where the Observers have enslaved humanity, as teased in last season's 19th episode, in which an FBI agent named Etta (Georgina Haig) attempted to free the ambered Fringe Division so they could save the Earth. It turned out, Etta was actually the grown-up daughter of Peter (Joshua Jackson) and Olivia (Anna Torv)!
In the new trailer for Season 5, we get a flashback to when the Observers first arrived on Earth, all while the Bishop family — which Olivia seems to finally be a part of (note the wedding rings) — attempts to enjoy a lovely day at the park. Considering that Peter ends up ambered and Olivia is MIA in 2036, this picnic won't end well. Check out the clip:
Fringe returns Friday, Sept. 28 at 9/8c on Fox.