One morning in 1933, on his way to school in a small village in eastern India, a teacher named Hanif Pathan happened upon a group of construction workers who, while doing some foundation work on a house, had discovered a terracotta pot containing a cache of silver coins. In the days and weeks that followed, Pathan started to look for more coins in a three-mile radius around his village, Bateshwar, in what is now Bangladesh, roughly 40 miles northeast of the capital, Dhaka.