DC's Legends Of Tomorrow ended its pilot season with the heroes killing the immortal tyrant Vandal Savage in three different time periods, thereby ending his reign of terror. After disposing of the meteors, Rip Hunter volunteered to protect the time stream and offered everyone a place on his team.
Firestorm, Atom, White Canary and Heat Wave assembled in 2016 to join Rip in a new quest, Kendra and Carter decided to hang up their Hawk wings and live a quiet life, now that Vandal Savage is no longer hunting them down.
Episode 16 ended with a Waverider appearing in front of them, which introduced another DC Comics character Rex Tyler/Hourman (played by Suits actor Patrick J Adams). Hourman arrived from the future with a warning about not to get on the ship. Adams's character revealed that he is a member of the Justice Society of America and that Rory and the rest of the team sent him to intercept their past selves.
Executive producer Marc Guggenheim spoke to TV line about the introduction of DC Comics hero Hourman and setting up the premise for the Justice Society of America. He said, "It was basically based upon a conversation I had with [DC Comics CCO] Geoff Johns, where we were talking about the variety of different characters Patrick could play. What's cool about Patrick's appearance is he's not just appearing as Hourman but he's also appearing as a member of the Justice Society of America."
"So for me, it was very much like, "OK, who's a character that I associate with the JSA? Who can show up, say his name, and I go, 'Ohhhh, JSA —that's cool'?" Certainly, Hourman is a key member of the JSA, at least the version of the JSA that I hold near and dear," he added.
In a separate interview with Hollywood Reporter, Guggenheim revealed more about the Justice Society twist, and how it sets up the season 2 plot. The producer shared, "With his [Hourman] final words in the finale, he planted a pretty deep flag about where we're headed in season two, which is not just introducing Hourman but introducing his teammates in the Justice Society of America. For comic book fans, everyone knows the Justice Society is really the precursor to the Justice League, so it's a pretty big move in our DC universe here on TV."