|Karloff as James Lee Wong|
These first five entries - Mr. Wong, Detective, The Mystery Of Mr. Wong, Mr. Wong In Chinatown, The Fatal Hour and Doomed To Die - were decent enough B-mysteries, a little lethargically-paced, perhaps, but okay time-wasters. When Monogram began production on their sixth Mr. Wong mystery - Phantom Of Chinatown - Karloff was, for some reason, unavailable. But, instead of casting another Caucasian actor (like Roland Winters, for example), Monogram actually hired Keye Luke - probably best known as "Number One Son," Lee Chan, in the 20th Century Fox Charlie Chan films - to take over the role.
|Keye Luke as Jimmy Wong|
Of course, Luke was in his early 30s at the time, and Karloff was in his 50s, so it seemed unreasonable to expect audiences to believe that Luke's Wong was the same Wong as Karloff's, so the characters call him "Jimmy" and Withers' Lieutenant Street acts as if he's meeting Mr. Wong for the first time. Now, for some reason unknown to me, Phantom was the last Mr. Wong film at Monogram (although the scripts would all be recycled when the studio got their hands on the Chan character a few years later), but it's pretty clear that they were setting things up to continue with Keye Luke in the lead.
Now, there were other film mystery series that replaced lead actors during the 30s-40s - Sidney Toler replaced Warner Oland as Chan at Fox, a couple of suave British actors took turns playing The Saint at RKO before and after George Sanders, Ralph Byrd took over for Morgan Conway as RKO's Dick Tracy after a couple of films, etc. - but there was generally no acknowledgement of the change, and, as far as I can recall, in no cases did they ever just act like they were starting over from the beginning!
Nowadays, "reboots" may be annoyingly trendy and way too common (a Spider-Man reboot? Already?) -- but the idea certainly isn't new.