With Billy's truck full of essentials, the Family are ready, packed and, for the first time this season, moving along together. With the plan still to head for the coast (which to me is taking ages. Even from Birmingham where its filmed you can get to the seaside in two hours) the open road is ahead. Well, for about three minutes, anyway, as a chance encounter with the victims of a roadside heist sees everyone diverted off the plan, to instead visit a rural country retreat for a little relaxation.

The ‘Valley', as it's known, is a hidden away refuge, an idyllic setting working as a co-operative commune, using the land and natural resources to help the 20 or so members live a happy, sunny existence picking fruit, having barn dances and generally making good of the situation they are in.

This wind down and welcoming break allows everyone some time to breathe and gives Al and Sarah an opportunity to tell everyone what they already knew, that the two of them are ‘loved-up'. But the general happiness of the family doesn't reach everyone, as Anya's friendliness with a local from the valley riles up Tom. This shows that the green-eyed monster of jealousy might well finish their relationship before it starts. 

Now, I can't tell if Max Beesley is a bad actor (he didn't seem to be in Hotel Babylon), but the more he plays Tom, the more robotic, clumsy and just dim he seems to be. As the series goes on, Tom seems to be devolving, becoming a dullard useful for killing people, regressing as a character to become a Cro-Magnon man rather than moving forward and developing.

His clumsy attempts to profess his love to Anya and his jealous rage all seem a little contrived, clumsy and badly written. And rather than try and talk things through (he has been with these people for the best part of a year), his monosyllabic attempts to show his caring side and all the moody brooding and threats just come across as lazy.

With everyone pitching in, Sarah is given the task of going to the outskirts of the Valley to get eggs. However, on her arrival she sees that the coops are full of chicken corpses. Instead of running or turning away, she enters the seemingly abandoned house the coop is by, and in doing so meets the dying family there who have caught a mutation of the original virus that wiped out the majority of the population. 

The result is Sarah, too, is infected and quarantined to the house with her fate inevitable as over the course of the episode she slowly dies and shows that her ‘uselessness' along with her initial unpleasantness and self survival were misplaced. For here she shows just how strong she is while at the same time breaking Al's and the rest of the Family's hears.

Played over the majority of the episode, her death is dealt with very well. Resigned to the fact that she will get ill and eventually die, Sarah puts her life in order, professing her love to Al and also talking about the future she isn't going to have. Well written, intelligent and poignant, this major element of this week's episode again shows how strong some of the writing is for the show (apart from the already mentioned two-dimensional Tom) and at times how dark the drama is. And while not as bleak as last week's, there is still enough clout to show that nobody in this new world is ‘safe'. 

Sarah's journey, however, isn't the only thing of interest this week as Greg wants to ‘go home'. It seems that his brush with death and the beginnings of creating a new family have stirred up something and the initial ‘loner' has pangs to see his family home one last time before he moves on. Taking Abby with him, the initially pointless drive out to the leafy suburbs does bear some fruit plot-wise, as Greg's former wife and her new partner had received a postcard with numbers (co-ordinates) on it. This was initially hinted at back in the first episode's Lost-style flashback to Greg's former life. However, now it seems this plot thread is being addressed and fleshed out.

The card's co-ordinates are for an airfield, a place where, apparently, the ‘chosen' people who were given the card were told to go to be picked up and transported away from the UK before the virus hit. 

Meeting an insane passenger who missed the flight, it appears that the government and those in power were told beforehand of the virus and those chosen and with cards were shipped to somewhere else. As much as he is a font of knowledge, the information stops, as the man, finding that Greg is not there to transport him out, blows his own brains out.

With this knowledge the couple return to the Valley just as Sarah is passing away, and after a small vigil, the Family are off again. For it seems Abby, after seeing the mutation of the virus and with the information gained from the man in the airport, decides that the only thing to do to stop or try and prevent the virus is to return to the lab she was abducted to at the beginning of the series.

However, it seems that the Family's initial fears that the virus is once again on the loose are confirmed, as the lab is abandoned and those who were left have all succumbed to the virus, dead without finding a cure - apart from Whitaker, who has Abby's son and the hook for the cliffhanger and series finale.

Once again, a strong episode and even the little things that are said in passing like noting that the virus could be, and probably is, spreading through wildlife all seem at first throwaway ideas, but are all woven into the tapestry of what's going on and the bigger picture in general.

Unlike, say, Lost, where you have to wait series after series to get answers, the fast pace and short seasons allow the writers to really speed up proceedings, answering things promptly and succinctly, providing clues, information and well developed story and character arcs that are logical and thought provoking. And, apart from Tom, who I feel is not going anywhere, each character and their place in the Survivors world is coming along nicely.

Check out our review of episode 4 here.