Lost Souls is an original BBC Radio 4 audio play written by Joseph Lidster. It aired on 10 September 2008 in the Afternoon Play slot as part of Radio 4's Big Bang Day. It celebrated the switching on of CERN's Large Hadron Collider that day. Andrew Marr introduced the audio play live from CERN. An MP3 version of the audio play was made available for seven days after broadcast. It was released on CD on 18 September 2008.