“Endgame” is episode seventeen of season one of The Tomorrow People.
At the end of the previous episode, “Superhero”, Stephen had found where Jedikiah was keeping his father’s body, cryogenically frozen. And Jedikiah discovered him there.
Jedikiah tells Stephen that he has been keeping Roger’s body hidden from the Founder, because the Founder wants to use him as a weapon using a machine. Something that the Founder wants to do to Stephen too.
Jedikiah wants Stephen to help kill the Founder, and to do that he needs the help of the Founder’s daughter, Cassie, who is in the Citadel that the Tomorrow People raided in the episode of that name. Everything that has been done is apparently part of a plan of Jedikiah’s, and possibly Roger’s. Which means that Jedikiah wasn’t as dense as he appeared to be regarding Stephen’s behaviour. He did seem to be quite unbelievably gullible.
There are flashbacks from Jedikiah regarding his time with Roger, from the first use of Roger’s powers in front of his brother 30 years ago, to their first meeting with the Founder. The relationship would appear to have deteriorated somewhat since then.
Meanwhile, Cara is tracking a new Tomorrow Person – her sister.