The world is changing fast in the fading frontier town of Penwyllt, and no-one knows this more than its unlikely heroes Margaret and Clive, who, like the other folk of the town, are plodding their way through life, with routines they've grown used to, full of faces they know and people they trust. 

But does anyone really know what's going on inside? Even those closest to you? 

Clive feels like he's becoming invisible – especially to his wife Margaret, who he knows is keeping secrets from him. But change is as good as a rest for the couple when they agree to look after Margaret's sister's cat when she and her husband Glyn head off on vacation. Maybe an impromptu night of drinking brandy and cavorting in front of the fire at the old manse will reignite this middle-aged couple's fading flame? 

Sgt Ruth Ellis and her less-than-reliable second in command, PC Eifion Richards, are called to the timber yard to investigate Glyn's torched-out truck, but they soon stumble on a bigger mystery, as Glyn seems to have disappeared into thin air. 

The pressure is all on Sylvia as Ruth calls at the manse to question her about missing Glyn – but guilt-ridden Sylvia hasn't seen her husband since the night of their huge bust-up, and she isn't about to reveal the whole truth to Ruth. 

With a rat in her skull, Ruth decides to pay Lefi a visit – but how much will he reveal about Glyn and Sylvia‘s troubled marriage, and does he have any idea who could have torched Glyn's truck?