Spoilers

The nature vs nurture debate is pretty definitively settled. The ballad of Dylan and Lilly comes to an end and Catherine makes a discovery that will change everything.

A deceptive amount happened in this episode, starting with the news about Sacha killing Ash coming out and that leading directly to Emily and family picking a side. It also neatly dovetails with Bill and Isla deciding that actually two wrongs do make a fight and Isla returning to her people. All of this is the exact level of bleak the show has always excelled at but Isla’s amazement at Bill’s sadness is a hint of where we’re going next. The invaders’ chosen beliefs are just that, beliefs. No plan survives contact with the enemy and that’s literally what Isla experiences here. Who knows if Bill’s sadness and empathy will have an impact on the war, but they’ve certainly had an impact on her.

However, the meat of the episode lies in Catherine’s discovery. The reveal that the invaders are time travellers neatly explains their biological nature and also goes a long way towards explaining their rage and hatred for us. While it’s not said out loud, there’s a hint of that resonating with the inescapable issue of climate change and the burnt planet younger generations will inherit. I hope the show steers hard into this because God knows it’s needed and it’ll suit the narrative we have like a glove.

Best of all though is the mystery of Dylan and Lilly. Angus Imrie is fantastic as Dylan and he cleverly plays into what we expect rather than what the young man is. Dylan is clearly a genius, clearly desperately in love and absolutely on the edge of the sort of nerd who stops being charming and starts being dangerous. But as the episode goes on we discover not only why Dylan was injured but that he cracked the invasion and he died painfully human. The implied murder didn’t happen, he just made a stupid mistake and Lily (Shalom Brune-Franklin who also impresses throughout) paid for it. But perhaps not fully…Dylan dies alone but he may have left us a new character and he’s definitely left us and the characters a key to understanding and stopping the invasion.

Verdict: Complex, nuanced character work in a complex, nuanced show that just maybe is starting to show the first rays of hope. 8/10

Alasdair Stuart