The Partyby Elizabeth DayLittle, Brown, 2017The party referred to in the title of Elizabeth Day's delightfully enjoyable novel is a gala affair thrown to celebrate the 40^th birthday of Ben Fitzmaurice, a charismatic, successful, and immensely wealthy businessman who's invited a group of revelers to his sumptuous country house for the self-congratulatory festivities. One of those guests is Martin Gilmour, a writer and art critic, who shares a long and complicated history with Ben dating back to their days in boarding school when Ben sheltered Martin from the predations of bullies and eventually introduced Martin to the rarefied world of the old Fitzmaurice money and landed estates. For all of those early, formative years, Ben and Martin are almost inseparable but never equal, as Martin later reflects:

I suppose it didn't help that Ben and I were so close. Difficult for any woman to come into that situation and hope to get my undivided attention. But, as I often told her, that's the way it had always been. Ben and I went way back. Best friends from school. So close we had, at one stage, been informally christened by his mother as 'Starsky and Hutch'. Later, Ben's wife Serena had coined a different phrase.'You're always there, aren't you, Martin?' she had said. 'Ben's little shadow.'

Naturally – this being a novel, after all – Martin's wife Lucy and Ben's wife Serena, confronted with a close friendship between two men, display the full complement of edged but muted antagonisms, and naturally – this being a novel, after all – that close friendship between two men must have a quasi-sexual and entirely unhealthy power imbalance … it must be at heart a sick relationship, and sure enough, Day's novel isn't four sentences along before readers are aware that something horrible has happened at Ben's party, and it involves dark secrets, life-long lies, and half a dozen other lightly-coded warnings to married couples to summarily drop all their acquaintances because having friends to whom you aren't married is just so strange, just trouble waiting to happen, etc. The secrets are obvious from very early on, but Day's skill at unspooling them is marvelous – it never flags, through even the most predictable scenes of police interrogations and narrators so obviously unreliable they're practically wearing clown masks.Readers of a snarky turn of mind might be tempted to dismiss The Party as a watered-down version of Brideshead Revisited in which some richly-deserved violence erupts in the third act – honestly, who, reading Waugh, doesn't want to biff a Marchmain? – but this sells short the real pleasures Day produces throughout this book. True, the actual framework of the plot creaks rather audibly, but the furniture and wall hangings are choice, and the social observations are enjoyably chilled:

A few years ago, Ben started saying y'know, eliding the two words to form a seamless whole. It was around the time certain politicians started eschewing the glottal stop in order to demonstrate their man-of-the-people credentials. I suppose it was intended to denote a certain informality, a lightness of touch, a sense that, in spite of Ben's enormous pile of inherited wealth and his aggressively successful hedge fund, he was in truth just an easy-going guy. Someone you could talk to. Someone you could kick a ball around with. Someone of whom one could say, 'Oh Ben, he's great. One of us. No airs and graces.'

The book's conclusion drastically accelerates the narrative's already-fast pace, and some rote comeuppances are deliciously withheld or subverted (we're to understand that one character's personal degradation has hit rock bottom when he becomes a book reviewer) in the final pages. This is a smart, smooth performance that hits its readers with social commentary and quippy prose in equal measure.