With a nod to 'Last Tango in Halifax', this 'last tango in Wales' is loosely based on Lisa's widowed Great-Granny Gladys, who got chatting to an elderly gentleman at the bus stop who turned out to be her childhood sweetheart. In Pondweed, pond supplies salesman Selwyn Robby arrives home one Monday afternoon towing the Toogood Aquatics exhibition caravan and orders his like-wife, Imogen 'Ginny' Dare, to get into the car. He's taking her on a little holiday, he says. To Wales. So begins their road trip west, via blasts from Selwyn's past, and a fortnight's journey of self-discovery for them both. But it's a fishy business towing this caravan, with its saucy mermaid curtains and fully stocked bar, and Ginny must untangle the pondweed to get to the bottom of it, even it does mean unearthing her own murky past to find out.