'Prague, 24th Century. The Doctor, Sarah and Harry arrive in a museum and discover one of the exhibits is actually a real person. They are arrested for the crime and the Doctor is allowed to investigate the murder. They discover that nanoprobes have been inbedded [sic] into the city, creating everything from cars to houses. The Doctor discovers that the victim was a master ballroom dancer. The killer had that knowledge downloaded into him. After narrowing down the list of suspects, the real murderer is caught.'
[The Doctor is the Fourth Doctor.]
Source: drwhoguide.com (http://www.drwhoguide.com/whotrip23.htm)