 The episode was written by David Fury and directed by Greg Yaitanes. According to series co-creator Damon Lindelof, discussion of both "Solitary" and the following episode, "Raised by Another", began in September 2004, when Lost debuted on television. The production team had fallen behind schedule, so Fury worked on "Solitary" while others went to a separate room to discuss "Raised by Another", with co-creator Carlton Cuse "bouncing between the two universes". Although production codes generally go in ascending order, "Solitary" had production code 107, while "Raised by Another" had production code 106. This was because, despite the broadcast dates, "Raised by Another" was written before "Solitary". The episodes were edited so that Sayid would return at the end of "Raised by Another". "Solitary" and "Raised by Another" were the first to orient the series in a "weird and mythological" direction, according to Lindelof. In "Solitary", the series solved its first mystery by revealing the origin of the French voice heard earlier. This reveal occurred despite the network encouraging the producers to wait until the finale to show Rousseau.
