In the early morning hours of March 18, 1990, two thieves pulled off the biggest art heist in history.

Disguised as police officers, they tricked a night watchman into letting them into Boston’s Isabella Stewart Gardner Museum, and made off with artwork worth nearly half a billion dollars.

The thieves have never been caught and the art has never been recovered.

Rick Abath was the guard who opened the door that night. Twenty-five years after the robbery, he sat down to tell his story with his wife, Diana.

Originally aired March 13, 2015, on NPR’s Morning Edition.

Photo courtesy of the Boston Police Department.