The Fourth Dimension
Planet of the Dead
Although the Doctor has never attempted to detect Rhondium Particles before, the Third Doctor used a Rhondium Sensor to detect Delta Wave Particles in The Time Warrior (1973/4).
The Stingrays operate in a similar way to the Nimon in The Horns Of Nimon (1980). In that adventure, the half man, half bull creatures persuaded civilizations to build black hole gateways between worlds for them. Having arrived on a new world, these 'intergalactic locusts' would drain it of energy before persuading another world to build a new gateway to allow their great journey of life to continue.
Thanks to a Time Lord gift, most alien languages are usually translated for the Doctor and those around him if he is nearby and conscious. Sadly that's not the case for the Tritovores. Another alien language that could that could not be translated by the Doctor was that of the reptilian Foamasi (The Leisure Hive, 1980).
If the original series of Doctor Who hadn't been cancelled way back in 1989, its 27th Season would have seen the introduction of a cat burglar called Kate Tollinger as the new companion for Sylvester McCoy's Seventh Doctor. An inspiration for Christina perhaps?
Located on the Southern shore of the Persian Gulf, Dubai is the second largest of the seven emirates that form the United Arab Emirates or UAE for short.
Appearing as mechanics, Cliff Richard and the Shadows (Hank B. Marvin, Licorice Locking, Brian Bennett, Bruce Welch) toured Europe on a London bus which they transformed into a motel on wheels in the 1963 film Summer Holiday. In the final episode of the 1984 cult comedy television series, The Young Ones are bored of their summer holidays and so decide to rob a bank making good their escape on a London bus which ultimately bursts into flames when driven off a cliff.
The No. 22 to Putney Common
Renegade Time Lady Iris Wildthyme who features in numerous short stories, novels and audio dramas, travels on a 20th century London 'Routemaster' double-decker bus (the No. 22 to Putney Common) which is in fact her TARDIS.
The bus is numbered 200 because, if you calculate things a certain way, Planet Of The Dead could be considered the 200th televised Doctor Who adventure.