1 [caption]: {a red-dotted line over Europe} Colonel Haken's zeppelin route to South America...
2 Me: {leaning over a map of South America with a red marker} Man, I need a professional historian and a cartographer to help with this comic...

BobP suggested this one. What cliffhangers-era story would be complete without a map with a dotted red line drawn on it?

The detail map of Europe is from the unsurpassed historical map collection in the Perry-Castañeda Library Map Collection at the University of Texas. The big map I'm leaning over is from the fine folks at National Geographic.

By the way, if you know your history, you'll realise that the first map is from the wrong time period, being specifically a map of Europe prior to the first World War. (That's why I need the help of a professional historian!) The country marked as Austria-Hungary didn't exist after WWI. I would have used a more appropriate era map, but had trouble finding one.