Rem Koolhaas must have been watching Gareth's 'Black Ball' performance yesterday because when we arrived at the opening of the Dutch architect's summer pavilion for the London's Serpentine Gallery, he'd erected what is effectively a huge balloon filled with hot air! Well, to be precise, the egg structure is filled with helium, which expands and contracts, causing the inner roof to rise and fall, according to the surrounding climate. To tie in with the current exhibition by the (well, what can I say, GREAT) Thomas Demand, they have taken the leaf-print wallpaper that derives from his recent series 'Tavern', whose ivy strewn wall alludes to a well-publicised German murder case, and papered the inside of the white dome's base. The 400 or so sweaty people drinking wine from their PAY BAR (come on, Rem, show us a bit of glamour!) may have missed the gruesome reference, but on a quieter night, it will be great to have a bit of Hyde parklife on the inside.