"Official" reconstructions have also been released by the BBC on VHS, on MP3 CD-ROM, and as special features on DVD. The BBC, in conjunction with animation studio Cosgrove Hall, reconstructed the missing episodes 1 and 4 of The Invasion (1968), using remastered audio tracks and the comprehensive stage notes for the original filming, for the serial's DVD release in November 2006. The missing episodes of The Reign of Terror were animated by animation company Theta-Sigma, in collaboration with Big Finish, and became available for purchase in May 2013 through Amazon.com. Subsequent animations made in 2013 include The Tenth Planet, The Ice Warriors and The Moonbase.