There were two main things to like about last night's Tomorrow People: Jedikiah putting a bomb up someone's nose, which will never get old. And the lovely scenes between John and Astrid, which prove that theirs is the only romance worth caring about on this show.
Sadly, the whole episode was geared towards getting John and Cara back together, despite their total lack of chemistry or lovability or what have you. The flashbacks in the episode were to when John and Cara first met, and he originally gained her trust when she was a pickpocketing urchin. The main arc of the episode is that Cara's arch nemesis Julian is back, trying to kill the Tomorrow People for Ultra with the aforementioned bomb in his nose, and John has to help Cara save the crew. And the episode ends with John disobeying Cara, but helping her to realize he's devoted to her and to what they built together. And rebuilding their relationship is a key step towards finding a way to stop Julian and his kill squad. So in the end, Cara and John are reunited and it feels so fine, while the mostly useless Stephen tinkers with his dad's old junk.
It's just too bad that the show dangled the possibility of John-Astrid awesomeness before making a left turn into John-Cara blahness. Why do you torture us, show?