Our hostess was Rose Fenton, the former director of the London International Festival, LIFT, who now runs the Free Word Centre, a sort of umbrella organisation for free speech and literacy organisations of which Index on Censorship is perhaps the most well known.
Fenton knew Klaic well - they had last worked together on the preparation for the candidacy of the Polish city of Lublin for the European Cultural Capital in 2016 - but she still gave the impression she was slightly intimidated by him. We all were, really, because he was so fearsomely impassioned in his arguments and opinions.
But the really great thing about him, and it shines through on every page of the book, which is called Resetting the Stage - sub-titled "public theatre between the market and democracy" - was the hard practical back-up he gave to his analyses. All of his knowledge and research was channelled in a living reality, and presented in the context of world theatre as a whole.
Thus his scintillating, brilliantly inclusive chapter on where and why theatre happens, a sense of its place in performance and social setting, ranges from a history of theatre architecture to a consideration of small or big, new or old, street or warehouse, gilt-edged or responsibly green - with informative insets about the Arcola in Dalston, Theatre Royal at Stratford East, factories in Germany, street theatre in Moscow, an art house in Paris and special use of urban sites in summer festivals.
"A five-hour-long production of Troilus and Cressida," he says, "in the summer of 2009 on a historic site in Skopje, Macedonia, resulted in the angry appearance of neighbouring residents in pyjamas, interrupting the performance with protests about the loud performance noise keeping them awake."
But of course, in former Yugoslavia, recovering from the upheavals and destruction of the 1991-95 war, any such sign of a return to cultural normality or, in this case, eccentricity, is an essential part of the healing process. For Klaic, all theatre is about repairing fractured communities and promoting international cooperation and understanding.
He became increasingly obsessed with the idea of an integrated European cultural project that still recognised the identity and civic responsibilities of its constituent states and nations. And of course, for him, only a public (ie, subsidised) theatre - not a commercial one - can make this happen.
What is so unusual about Klaic is that while you feel that his heart and mind are more powerfully engaged by the public theatre, he is fully appreciative - in the sense of understanding, and defining what exactly it does - of the commercial theatre, too.
He can tell you precisely how the boulevard theatre works in Paris, why Chicago was such a big hit in Moscow, how producers work within elaborate corporate structures and why Joop van den Ende's Stage Entertainment - which owns 35 companies, 25 large venues and a Broadway complex - is one of the biggest live entertainment businesses in Europe.
I first met Klaic at the BITEF festival in Belgrade, where his galvanic interventions at round table discussions with the leading theatre directors of the day - Peter Brook, Jerzy Grotowski and Robert Wilson, right through to Eugenio Barba, Andreij Wajda and Peter Sellars - made an indelible impression on the way I thought, and indeed wrote, about theatre.
Similarly, there's not a page in his new book that won't stimulate an argument in any theatre gathering. He has the rare gift of making you realise what you think about theatre, and it's not necessarily what you already know.
Rose and her colleagues laid on a fine spread of home-made cakes, champagne and hot drinks, while writers and friends mixed happily in the light-filled Swedish-style reception room. Klaic's great friend, Goran Stefanovski, playwright and teacher, refuses to accept that he's gone. And he's right in the sense that you feel the need all the time to know what Dragan might have thought about this, or written about that. And in feeling that, you can already begin to imagine his response....