In the aftermath of episode two's dramatic events, Kieran (Luke Newberry) has fled his family home and Rick (David Walmsley) is being forced to choose between his human family and his 'rabid rotter' compatriots.
Kieran eventually finds himself back at the supermarket - briefly glimpsed in episode one's opening sequence - where he and Amy (Emily Bevans) stalked and killed Lisa Lancaster (Riann Steele). Back then, Jem (Harriet Cains) - despite all her bluster - was unable to kill her zombified brother when she had the chance.
It's a decent twist, explaining just why Jem's been so aggressive towards Kieran - not only did she watch her brother kill her friend, but she found herself unable to stop him and as a result resents herself as much as she resents him.
As Jem cracks, Harriet Cains does her best work - she and Luke Newberry work brilliantly together, and there's a real, genuine warmth to their interaction.
Afterwards, Kieran determines to make amends with Lisa's family, but has to make a very different confession than the one he'd planned. Lisa's parents are happy to accept that Kieran attacked their daughter, but only because they believe she will return as a PDS sufferer and can't accept the truth - that she's gone for good. It's the sort of bizarre, almost comical moral ambiguity that only a show like In The Flesh could explore.
Rick, meanwhile, is becoming increasingly wary of Bill (Steve Evets) and ultimately casts off his human disguise entirely to defy his father - a bold choice that costs him dearly. David Walmsley is a real talent - witness the fantastic scene in which he conceals the 'bad side' of his scarred face - and it's a shame that we didn't get more Rick this week. But more on that later.
I'd initially suspected - given Rick's impressive knife wielding - that he'd be forced to kill his father, but in the event, writer Mitchell opts for a crueller climax, with deranged Bill killing his son and dumping him on Kieran's doorstep, before retreating inside himself to erase all knowledge of the crime.
Steve Evets and Luke Newberry are fantastic in the confrontation that follows, and Ricky Tomlinson's Ken Burton later blowing Bill away as an act of retribution for his wife's murder is a wonderful moment - though I could have done without the clumsy metaphor of Bill literally having blood on his hands.
The devastation of the Macy family brings this initial three-episode run of In The Flesh to a grim yet fitting end, but so, so much is left unresolved or only half-explored. The unlikely romance between Amy and Philip (Stephen Thompson) is a development that comes out of nowhere and subsequently goes nowhere - a consequence of the limited three-episode run.
The fact is that Dominic Mitchell just has too many ideas to cram into such a brief trilogy. Some characters get their due - Marie Critchley gets two sensational monologues this week as Luke's mother Sue Walker, but Amy - who leaves Roarton to find the Undead Prophet - only has a few short scenes, though her interaction with Kieran again feels heartfelt and genuine.
The short run sees so much talented go under-utilised - veterans Ricky Tomlinson and Kenneth Cranham are sidelined, while talented Skins star Alex Arnold is relegated to a cameo - and many story threads - Kieran and Jem's renewed relationship, the Undead Prophet - go unresolved.
Dominic Mitchell has spoken openly about having penned a series bible that plots out the mythology of future seasons; In The Flesh was a truly unique drama and undoubtedly a risk for BBC Three, but it's a risk that paid off. Now the Beeb needs to take another risk and cough up the cash for series two.