Inside Merlin's Library the set dressers placed two desiccated bodies. None of the characters address the presence of the bodies and the actors themselves missed seeing them.
Meurik's wife was played by a contest winner. They cast her as the wife to ensure that she would remain in the episode and not on the cutting room floor.
The Russian BC-304 Korolev is named after Sergei P. Korolev, the lead Soviet rocket and spacecraft designer during the 1950s and 1960s.
Among the treasures in Merlin's library is a very Egyptian gold pyramid.
Katharine Isabelle who plays Valencia, plays a teenager, but is actually in her mid 20s at the time of filming.