War clouds were very obviously starting to gather around Europe at the time that Arrest Bulldog Drummond -- completed in 1938 and issued in January of 1939 -- was released. John Howard plays the adventurer hero of the title and H. B. Warner portrays his friend Colonel Nielson of Scotland Yard. This time the case involves an experimental ray machine that can cause explosions at great distances -- and the man behind it all is Rolf Alferson, played by veteran British character actor George Zucco (who made a career out of playing mad scientists, mad cultists etc. -- the operant word being "mad").