The post office was a small, square building on Teal Street, just off Main. It had 500 mailboxes, 340 of which were rented to Amity’s permanent residents. The other 160 were allotted to summer people, according to the whims of the postmistress, Minnie Eldridge. Those people she liked were permitted to rent boxes for the summer. Those she didn’t like had to wait in line at the counter. Since she refused to rent a box to any summer person on a year-round basis, summer people never knew from one year to the next whether or not they would have a mailbox when they arrived in June.

It was generally assumed that Minnie Eldridge was in her early seventies, and that she had somehow convinced the authorities in Washington that she was well under compulsory retirement age. She was small and frail-looking, but deceptively strong, able to hustle packages and cartons nearly as quickly as the two young men who worked in the post office with her. She never spoke about her past or her private life. The only common knowledge about her was that she had been born on Nantucket Island and had left sometime soon after World War I. She had been in Amity for as long as anyone living could remember, and she considered herself not only a native, but also the resident expert on the history of the town. She needed no prodding at all to embark on a discourse about Amity’s eponym, a seventeenth-century woman named Amity Hopewell who had been convicted of witchcraft, and she took pleasure in reciting the list of major events in the town’s past: the landing of some British troops during the Revolution in an ill-fated attempt to outflank a Colonial force (the Britons lost their way and wandered aimlessly back and forth across Long Island); the fire in 1823 that destroyed every building except the town’s only church; the wreck of a rum-running ship in 1921 (the ship was eventually refloated, but by then all the cargo off-loaded to make the ship lighter had vanished); the hurricane of 1938, and the widely reported (though never fully ascertained) landing of three German spies on the Scotch Road beach in 1942.

Ellen and Minnie made each other nervous. Ellen sensed that Minnie didn’t like her, and she was right. Minnie felt uneasy with Ellen because she couldn’t catalogue her. Ellen was neither summer folk nor winter folk. She hadn’t earned her year-round mailbox, she had married it.

Minnie was alone in the post office, sorting mail, when Ellen arrived.

“Morning, Minnie,” Ellen said.

Minnie looked up at the clock over the counter and said, “Afternoon.”

“Could I have a roll of eights, please?” Ellen put a five-dollar bill and three ones on the counter.

Minnie pushed a few more letters into boxes, set down her bundle, and walked to the counter. She gave Ellen a roll of stamps and dropped the bills into a drawer. “What’s Martin think he’s going to do about that shark?” she said.