It’s an anonymous, single owner sale with two overriding themes unlike anything else you will have ever seen.
The guy was seriously into bears and skulls and collected them from all over the world for many years: from Renaissance skulls and a resin skull oozing roaches and maggots by Jake and Dinos Chapman (estimate £20,000-£30,000), to a 1950s American novelty polar bear cocktail shaker (estimate £400-£600).
Works by Allen Jones, Damien Hirst, Tracey Emin and Rothko make this a more serious proposition, too. The galleries have been dramatically redecorated to chime with the eerie theme: downstairs the walls are lined with thick, transparent- and red-plastic striped blinds, while upstairs there's neon lighting and skull-themed wallpaper.
All 650 pieces will go under the hammer from 10–12 March, but until midday on 10 March you can see it all for free.
This Friday, Bear Witness stays open till midnight, with a pay bar, DJ and hourly guided tours from 6pm. Add your name to the guest list here.