Tensions are high at the Stone household as Ben’s quest to find the missing passengers gets more urgent when one of them turns up on his doorstep. Can he, Michaela and Vance find the others in time to save them and Cal from the experiments being carried out on them?

So the gang have found exactly where they believe the experiments are being carried out on the missing passengers, and Ben is all for going there immediately to put an end to the whole thing. Vance, however, is more cautious, reasoning that they should gather intel and be sure of themselves so that their quarry doesn’t flee a second time.

That timetable gets stepped up slightly when one of the missing staggers into Ben’s driveway begging for help, saying that the voice told her to seek him out. Her confirmation of what’s being done to the rest of the missing is the motivation Ben needs to push even harder to go in, and in the course of persuading Vance he’s forced to share more information with the NSA chief than the others – Saanvi especially – are comfortable with. Still, having done so, Vance is on board and the mission is a go.

Meanwhile back at Chez Stone, Grace has organised a little gathering of Ben’s friends so that he can have a bit of normality after the plane and all the long hours he’s been working lately. Of course, his sudden new enthusiasm for the mission inevitably means that he won’t make it there, but someone else does, and what they have to say to Grace is a bit of a shock for her. That shock is made worse when it turns out that Cal has gone off to find his Dad, leaving a note behind.

What’s good here is that the mission itself – which could have been rather straightforward and anticlimactic – is actually made more interesting by several additional factors, not the least of which is Michaela’s ongoing conviction that anyone from outside the group who is told of the callings is in mortal danger. Add that to some other quirks and suddenly instead of just ‘go to place, storm with soldiers, rescue passengers’ we get a far more nuanced and tense situation for our heroes to face off against.

And added to that is the ongoing sense of domestic drama surrounding everything. Ben and Grace’s marriage will once again be put under strain as he is forced to make choices she simply cannot begin to understand. Include the volatility provided by the fact of Cal’s illness and their respective protectiveness towards him from their own perspectives and it can’t help but be fascinating TV.

Explosive too. As usual, there are an awful lot of moving parts here, and though there are some twists (one major one in particular) there’s always a sense of the writers playing fair. Reflect on everything you’ve seen once the credits roll and you’ll realise all the clues were there threaded through the episode – they just weren’t being waved in your face the whole time.

Verdict: Pacey, intense and never lacking for different levels to its drama. This is one show that’s solidly consistent week after week. 8/10

Greg D. Smith