The heroes are set to uncover the two vital ingredients to take down Savage in "Legends of Tomorrow" season 1 episode 13.

"Legends of Tomorrow" season 1 episode 13 is entitled "Leviathan." According to Spoilers Guide, the team is set to learn the two key elements that they need to defeat Savage - these are the villain's daughter and the means to kill him for good.

As per the publication, Rip is also set to transport the team to a 2166 London, which is revealed as three months prior to the death of his family. The episode unveils that Rip believes that it will be their last chance to defeat Savage; otherwise, their future is going to be in peril because the villain's power is at its peak.

"Legends of Tomorrow" season 1 episode 12 is entitled "Last Refuge." In the episode, the team was locked in by The Pilgrim, which is a deadly assassin who wanted to eradicated the team from the time table through killing their younger, non-superhero selves. This way, they will no longer be able to exist in the future.

As per Spoilers Guide, Rip protected the heroes by telling Sara, Snart, Rory, Professor Stein, and Jax to abduct themselves first prior to being killed by the villain. The time traveller also instructed them that he knew a refuge for their younger selves. The place was an orphanage where future Time Masters were raised and where Rip grew up.

"Legends of Tomorrow" season 1 episode 13, "Leviathan," is set to air on Apr. 28.