“Thanatos” is episode eight of season one of The Tomorrow People.
Thanatos was mentioned in the vision Stephen had of his father in the previous episode, “Limbo”, whilst he was drowning. Thanatos is the personification of death in Greek mythology.
At the beginning of the episode it goes back to the time when John underwent the experiment at Ultra that resulted in him having the ability to kill others, unlike the rest of the Tomorrow People, that was revealed in “Kill or be Killed” – something that it appears that Stephen’s uncle Jedikiah may have regrets about, as he does seem to have some possibly genuine feelings for John.
Stephen thinks Thanatos was a project that his dad was involved with. Cara decides to read Jedikiah’s mind whilst he is asleep to find out more – which requires breaking in to his apartment and, given his defences, that means they can’t use their powers to teleport in. Which results in an unanticipated and unwanted outcome.
More of Jedikiah and John’s past association is disclosed, and Stephen meets the Founder – the Tomorrow Person who helped found Ultra with Stephen’s father and uncle.