As part of the new cult Perplex City alternate reality game, the ultimate prize of which is a bounty of £100,000, this Saturday people from all over the world will be coming together in London to collectively track down a dangerous organisation through an intricate puzzle treasure hunt.

A sharp intellect, quick legs and most importantly, imagination will be the qualities needed to succeed. Anyone can take part. We can't tell you what's going to happen, but you can be sure it will be an adventure!

Come along - and expect the unexpected...

* Location: Clapham Common - North East Corner, at the corner of Long Road and Clapham Common South Side ( )

* Date: Saturday 22nd October

* Time: 2pm - 5pm

* Cost: Nothing

* Dress code: Wear something purple!

* Visit and for more essential information

Perplex City background: The Perplex City game is played online in the first instance, with players buying silver packages that each contain six cryptic puzzles. Each card carries an unusual game or puzzle which, once solved, provides the player with clues towards helping the people of Perplex City recover the cube. Players enter their solutions online at and receive a certain number of points, depending on the difficulty of the card. This virtual world spills quickly into the real world with interlinked clues appearing in baffling websites, coded newspaper ads, TV clips, cryptic phone calls, and urban treasure hunts around the world such as this one, as people work together to solve the ultimate mystery of where the treasure is buried.