Very prim and proper. The DVD box set has the longer version of this made-for-TV movie at over 3 hours and this one is packaged first. Christopher Lee at around age 70 is Sherlock Holmes on the cusp of retiring. Patrick Macnee of The Avengers is the trusty Dr. Watson who through his stories of their adventures has turned Sherlock into quite a celebrity in 1910. King Edward has Mycroft bring Sherlock to his office and assigns him to help transport a diamond from South Africa to England. So, this mystery doesn't take place around London and 221B Baker Street. Holmes and Watson take a cruise to Africa. Mycroft has supplied a fake diamond for Holmes to switch with the real one so crooks can't steal it from the safe, but a team of thieves get to the real diamond before Holmes makes the switch. Or did he already make the switch? At the hotel in Cape Town Sherlock begins to identify some suspects, as well as red herrings, but must follow the clues on a train to Victoria Falls. It turns a little Murder on the Orient Express. There are British suspects, Indian suspects, African native suspects, an Italian inventor of wireless communication, and even a couple American suspects on the train. One of the Americans is retired President of the United States, Teddy Roosevelt, on safari in Africa with a new moving picture camera novelty. Turns out the plot has to do with a large treasure somewhere in an African cave and most of the team of thieves responsible for stealing the diamond turning on each other.