With some sort of global apocalypse having occurred up top, a family have taken refuge deep inside a salt mine where dad’s previous profession in the energy sector has ensured that they live a civilised and well appointed life. With Reubens and Rembrandt augmenting their oak-clad walls, Michael Shannon and Tilda Swinton have brought up their son, George MacKay, with the help of her best friend Bronagh Gallagher, a doctor (Lennie James) and their gay butler (Tim McInnerny). They spend their days rehearsing for disaster scenarios and rearranging their home, whilst the son writes a memoir for his father that marries an (environmental) history of the world with a curiously slanted homage to the efforts made by his father to provide unlimited cheap energy to the masses! Then one day, this Elysian dream becomes compromised by the arrival of a young girl (Moses Ingram) and that puts them into a quandary. Do they let her stay or do they evict her back from whence she came? If she stays, how might she upset the dynamic amongst a family who have clearly only a wafer thin sheen over a multitude of issues from their respective pasts that have largely been forgotten for then twenty-odd years they have lived their subterranean existences? There is singing, and a lot of singing - and with the possible exception of Ingram, none of them are very good at it. That doesn’t matter, though, as the score from Marius de Vries and Josh Schmidt combines just about everything from Rachmaninov and Gershwin to Lloyd-Webber, Rice, Pasek & Pau. Once your ears get used to the sometimes grimace-inducing falsetto of an enthusiastic MacKay and an on-form but fairly tuneless Swinton then this actually works quite entertainingly. Gallagher can always be relied upon to add a little vitality to a story and McInnerny also knows how to ham things up (just as he did in “Gladiator II”) to good effect, too. The timelines jump now and again, but never by much and it has quite a quirky effect on the delivery as characters appear to, well, disappear, at the end of the scene. MacKay steals this for me, delivering a role that reminded me a little of Luke Treadaway’s Olivier award winning stage effort as “Christopher” from “The Curious Incident of the Dog in the Night Time”. His journey to adulthood being tempered by a very slightly autistic characterisation; a dependant relationship with his mother and his own clearly awakening hormonal desires, too. It’s long, and at times can be a bit hit or miss - but generally it does flow along well, in a very theatrically staged fashion and if you are looking to see something that takes just about everyone from their comfort zone, then this might be for you.