After a rip-roaring success of an Edinburgh debut with their 2016 show Victory Flaps,  Flo & Joan (otherwise known as Nicola and Rosie Dempsey) are back with another hour of playfully but artfully constructed songs, poking fun at a variety of subjects from sisterly euthanasia to the loneliness of the single life and a wide array of unexpected tangents in between.

The pair freely admit that last year was something of a rollercoaster for them, achieving a TV appearance in Canada (their former place of residence), being shortlisted for the Amused Comedy Award at the 2016 festival and even creating a viral video that garnered many millions of views online. It’s strange, then, that they’ve relocated from the basement of The Newsroom to a similarly cloistered (but perhaps better located) spot in the bowels of the Tron, which if anything appears to be a step down in size.

Regardless of the venue, the sisters’ winning personality is evidently intact from the offset, immediately disarming the crowd through an opening number packed with rhetorical questions about the foibles of modern life. They then return to the subject of their failed love lives thus far (a favourite mining ground for material last year) with a song about European romances, before rushing on to a stand-out skit where they discuss how each of them would do away with the other should the situation warrant it.

There are a few returning favourites from 2016, including a eulogy to bees and some witty interplay between the songs, but for the most part, the material is fresh from the oven. The subjects are so off-the-wall and diverse that they could quite easily have been chosen by a tank of manatees, but the execution itself is clearly painstakingly constructed. Even when the overarching jokes and themes seem precariously flimsy, the cartwheeling lyricism and irresistible charisma of the two keep the audience onside.

Nicola reveals (perhaps jokingly, perhaps not) that she is the proud owner of a music degree and the not-so-proud owner of tens of thousands of pounds’ worth of debt, and the technical ability in parodying various genres and styles is all too obvious. This, alongside the easy charm, intense wordplay and uncanny knack of pulling out of the telegraphed punchline of a joke for a darker, quirkier and even funnier finale is what makes this act stand out from the Fringe throng.

With comparisons to double acts such as Flight of the Conchords and Garfunkel and Oates certain to swell as their compendium does, is a TV series in the offing? If they continue to plunder the depths of their imagination with similar dexterity and talent in the future, and with the highly relatable quest for love a central theme, the idea certainly has legs. Watch this space.