By Philip Z Loh and Greg Pliska

Solvers are given a list of metro station names, and a quick glance reveals that they must be from different cities around the world (a reasonable conclusion given the existence of Arabic and Chinese characters). Solvers go to town finding possible world cities that these stations could be located in, and some are, by design, ambiguous (e.g., the Phoenix station should ultimately be placed in Singapore!). Eventually, solvers find that there is only one way to place every station on the map such that the station’s line color and unique markings (e.g., there is an Amtrak connection at Boston’s Back Bay and an R-line connection between Madrid’s Príncipe Pío and Ópera) match that in real life and such that each city is spatially contiguous on the map.

That map is presented here: The map (solution)

Solvers then use the number of stations a city has on each line to index into the city's name for a letter (e.g., Singapore gives both a blue N and a gray E). Chaining letters together by line, traveling in the direction of the “spatial incontiguity” arrows, yields a word. Reading the words by line in resistor color order results in the phrase “HE MADE THE TRAINS RUN ON TIME SURNAME.” That mythical man is the answer to the puzzle, MUSSOLINI.

2ETAIPEI5松山機場, 中山國中, 南京復興, 忠孝復興, 大安
2 RED3MHAMBURG3Burgstraße, Berliner Tor, Hauptbahnhof
4ACHICAGO5Fullerton, North/Clybourn, Clark/Division, Chicago, Grand
5DMADRID6Noviciado, Santo Domingo, Ópera, Sol, Sevilla, Banco de España
6EBUENOS AIRES3Dorrego, Malabia, Ángel Gallardo
3 ORANGE7TBOSTON4Roxbury Crossing, Ruggles, Mass. Ave, Back Bay
8HPHILADELPHIA2Walnut-Locust, Lombard-South
9EST. PETERSBURG4Ли́говский проспéкт, Достоéвская, Спáсская, Театра́льная
4 YELLOW10TAMSTERDAM4Spaklerweg, Van Der Madeweg, Station Duivendrecht, Strandvliet
11RFRANKFURT2Nieder-Eschbach, Bonames Mitte
12ASHANGHAI3曹杨路, 金沙江路, 中山公园
13IMADRID5Sol, Callao, Plaza de España, Ventura Rodríguez, Argüelles
14NTORONTO5Lawrence, Eglinton, Davisville, St Clair, Summerhill
15SWASHINGTON3L’Enfant Plaza, Pentagon, Pentagon City
5 GREEN16RCAIRO4Attaba العتبة, Nasser جمال عبدالناصر, Maspero ماسبيرو, Zamalek الزمالك
17UHAMBURG5Hauptbahnhof, Berliner Tor, Landwehr, Hasselbrook, Wandsbeker Chaussee
18NWASHINGTON6Congress Heights, Anacostia, Navy Yard-Ballpark, Waterfront, L’Enfant Plaza, Archives
6 BLUE19OCAIRO5Ghamra غمرة, Al-Shohadaa الشهداء, Orabi عرابي, Nasser جمال عبدالناصر, Sadat السادات
20NSINGAPORE3Bukit Panjang, Cashew, Hillview
7 VIOLET21TST. PETERSBURG2Адмиралте́йская. Садовая
22ICHICAGO3Wellington, Diversey, Fullerton
23MMANILA1Betty Go-Belmonte
24EBARCELONA5Universitat, Passeig de Gràcia, Tetuan, Monumental, Sagrada Familia
8 GRAY25SWASHINGTON3Federal Triangle, Smithsonian, L’Enfant Plaza
26USAO PAULO6Quitaúna, General Miguel Costa, Carapicuíba, Santa Terezinha, Antônio João, Barueri
27RMADRID4Argüelles, Príncipe Pío, Puerta del Ángel, Alto de Extremadura
28NLONDON3London Bridge, Bermondsey, Canada Water
29ALOS ANGELES4Carson, Harbor Gateway Transit Ctr, Rosecrans, Harbor Fwy
31ESINGAPORE9Phoenix, Bukit Panjang, Senja, Jelapang, Segar, Fajar, Bangkit, Pending, Petir