The second series of Channel 4's Utopia is due to start tonight, returning to the mystery surrounding Janus and The Network.

But what happened in the end of the first series?

In the first series, a small group of people are thrown together through their appreciation of a graphic novel The Utopia Experiments. They go on the run after The Network infiltrates their lives, turning them into fugitives, at which point they meet Jessica Hyde – a woman who has been on the run from The Network her whole life.

They soon discover The Network infiltrates all parts of society. Working to find out what their plan is, the group sets up in a derelict manor house and try to decipher the secret meaning of the manuscript, a part of the graphic novel.

It later emerges that The Utopia Experiments was written by group member Jessica's father. We also discover one of the men hired to track the group down and kill them is her brother Arby. While Jessica was able to escape and was raised by a man named Krystos, Arby was not so fortunate. Before dying at the end of the second series, he tells Jessica: "Don't do what I did. Don't find out the truth about our father."

Mr Rabbit and Janus

utopia series 2
The first episode of the second series goes back to the 1970s, when Milner meets Carvel Channel 4

Throughout the series, the group is trying to find out what Janus is and who Mr Rabbit is. Janus, it emerges, is a vaccine of sorts given to people to curb the world's population by making them infertile. It would affect about 95% of the population, halting the spread of mankind.

The group believe the secrets of Janus were hidden inside the manuscript and fight to keep it out of the hands of The Network.

Mr Rabbit's identity – thought to be the leader of The Network – was more of a conundrum that left you guessing until the end. It eventually transpires it is Milner, who had tricked the group into thinking she was on their side, working against The Network.

At the end of the series, Jessica takes the manuscript to Milner, unbeknownst of her true identity, to hand it over. On realising her error, Jessica tries to leave but is trapped. Milner then tells Jessica that Janus was never concealed in the manuscript, but was hidden inside Jessica herself.

Grant, Becky and Ian

Grant, Becky and Ian were left at a train station. Becky, who throughout the series was plagued by a mystery illness for which she had to take an equally mysterious medication called Thoraxin, notices symptoms coming back. Instead of leaving with Grant and Ian, she hops on another train alone, sparing them from seeing her (possibly) die.

Michael Dugdale

utopia series 2
A host of questions were left unanswered at the end of the first series Channel 4

The civil servant, who largely started the whole series after impregnating a prostitute, gets blackmailed by The Network to order huge amounts of useless drugs, leading to the resignation of the current health minister (in order to get a Network operative in the position).

Towards the end of the first series, it emerged the prostitute was never really pregnant and was in fact from The Network. Michael leaves the end of the first series with Alice, the young girl Grant befriends after going on the run, after helping the group burn down a shipping warehouse where the vaccine was being held (we think).

Remaining questions

Is Wilson dead? He is stabbed by Jessica in the end of the first series having decided the purpose of Janus is just. However, we never see him die.

Who are Jessica's parents? Some have suggested it is Milner, but the mystery remains.

Is there a cure for Becky's illness?

What is hidden in the manuscript? While Janus is inside Jessica, questions remain over why The Network tried so hard to find the manuscript and what it contained.

Utopia is on Channel 4 at 10pm tonight (14 July)