Here we are in series 2, and the writers still refuse to address the most likely, source of a terror attack in the UK, they're obviously scared stiff of upsetting a certain demographic of UK society, so they make up far fetched storylines instead.
That isn't to say this isn't entertaining nonsense, but that's what it is, nonsense with seemingly very little basis in reality.
Also, the acting is as wooden as a rocking horse, I certainly don't get the fuss about Vicky McClure, she seems one of these actors who just play the same part time and time again.
If you're looking for an easy, no need to concentrate watch, then this could fit the bill, otherwise look elsewhere.