We almost didn't make it. When we tried to check in for our flight at Seoul Incheon Airport, the lady at the China Airlines desk asked us for our visas. We told her we were planning to obtain one of the new 144-hour visas upon arrival, but she looked perplexed. "You can only travel to one city with those kinds of visas. With your layover in Tianjin, that's two cities." Huh? Why do you need a visa for a layover? The answer to that question is a phrase we used a lot in the next few days: "Because, China…"