The original cast of The Hitchhikers Guide to the Galaxy will reunite for  BBC Radio Four’s Character Invasion  for a special live performance. Some of the nation’s best loved characters will be popping up in unexpected places today as part of Radio 4’s Character Invasion. The station will host a day of fun, celebration and considered conversation about what character is and what it takes to create them. There will be a range of activities both on-air and in and around BBC Drama across the country.