In just a few hours, the Legends will embark on the most important mission of their lives–traveling back to 1916 and preventing the Legion of Doom from getting their hands on the Spear of Destiny. The catch: running into their former selves can make time fold in on itself and cause a paradox that will potentially destroy the universe. No big deal.

The photo gallery for the season finale looks very similar to the one from ‘Fellowship of the Spear’. The team is back in their war uniforms, interfering in the Battle of the Somme. (Bonus: be prepared to run into Jack Turner’s J.R.R. Tolkien again.)

The trailer for the episode shows the Legends fighting themselves, Rip (Arthur Darvill) dealing with his…small…predicament, and Black Flash wreaking havoc. Things certainly aren’t looking good for the Reverse Flash (Matt Letscher).

The first sneak peek for the episode shows the team trying to communicate with their former captain…only to find out that getting back on the Waverider won’t be as easy as they thought.

The second sneak peek shows Doomworld’s Thawne informing his team about the newest development with the Legends.

Finally, executive producer Phil Klemmer explains the Legends’ latest dilemma in the inside featurette for the episode.

‘Aruba’ airs tonight at 8/7c on The CW.