At 27:06 on the horizon you can see in the background the training ship Empire State VI, which belongs to the State University of New York maritime college at Fort Schuyler. This college trains national and international students on its Throgs neck Bronx campus, to be the worlds merchant mariners. It has been rumored over many years that there are secret tunnels between Fort Schuyler and Fort Totten.
The jewel is found in Fort Totten. Supposedly it was named for a Civil War fighter but it also has another meaning. Tot is German for death and considering the lengths that the group went to find the jewel the name is appropriate.