Mind. Blown. Zut alors! How is this possible?! Such was Catherine’s reaction to realising that the Invaders had travelled to Earth not through space, but through time. It was a total revelation for the physicist – proof of concepts previously held only in theory. For Dr Durand, it changed everything. Catherine’s amazement was enviable, because for us, it changed nothing. Ever since Emily’s tattoo was spotted on the arm of that dying alien in the season one finale, it’s been taken as read that the Invaders were time travellers (time travel being a much less rare phenomenon to encounter for sci-fi TV fans than it is for French astrophysicists). Observatory Invader Micah confirmed as much when he told Catherine earlier this season that their journey to Earth had taken no time at all. After spending so long learning nothing new, viewers crave the kind of game-changing revelation Catherine has just had. The Invaders continue not to give anything away. There are only two episodes left in this season (which will be followed up by a third, announced this week) and still they’re little more than a mostly interchangeable mass of murderous intent. They have one Terminator-like setting: to kill Bill Ward, which appears to be it for them. Even after Bill saved Isla’s life, she still went at him with that ashtray, so relentlessly ingrained is their mission. If so, Jonathan throttling one to death won’t have gone any way to correcting them. Not that he had any real choice in the matter. With his son held at gunpoint, it was a classic ‘us or them’ scenario. That appears to be the theme of this whole season, which, drilled down, seems to be about the lengths we go to protect our own and to survive. To that end, episode six did offer some story progress in that Emily has picked a side now. She volunteered to let Bill extract the virus from her blood in order to wipe out the aliens. Her mind was made up when little brother Tom was wounded and she realised that she’d do anything to save her family – up to and including genocide. That puts her precisely where the Invaders stand on the subject. Is this all heading towards a pacifist moral lesson about the dangers of tribalism? Dylan and Lilly’s story in the lab doesn’t fit under that heading. That functioned as a mini-mystery, complete with its own red herrings. Dylan didn’t cut his wrist, we learned, but was stabbed by experiment subject ‘Bob’, who caught Catherine with the same crafty trick. Dylan also didn’t kill Lilly in a jealous rage for cheating on him, although things were made to look that way for a while (the show must have been getting a bit too light and hopeful, requiring a shot of added bleakness). Dylan locked Lilly out of the lab, perhaps sealing her fate, perhaps leaving her out there to reappear as a potential future cast-member. If War of the Worlds’ aim isn’t to tell a contained story but to run and run The Walking Dead-style, then Dylan and Lilly’s story is a template for how to introduce new characters to this apocalypse. Speaking of young love, the news that Sacha killed Ash seems to have put the kibosh on the series’ other romance. Sensibly, Emily walked, and Sacha followed secretly along behind the group, like Gollum hungering for his precious. It felt like an intake of breath, this episode, in preparation for a (hopefully) dramatic ending. Most of this series has felt that way, like a run-up towards something big. After a busy opening, it’s kept its secrets and given very little away, moving the plot forward in as small increments as it can allow. Next, it’s surely time for our two scientists to meet, and for the Invaders to give us something other than their ‘Kill Bill’ directive.