The Folger Adams keys taken from Jack Sylvane and Cal Sweeney under a laser analysis.
These keys are used to open a secret, underground room on Alcatraz Island beneath the lighthouse. There are three separate keys: two keys are similar to each other and are large, silver Folger Adams keys. Folger Adams keys were invented in the mid-1800's but Emerson Hauser's laser analysis of these keys in 2012 concluded that they required "modern technology" to be made. The third key is an old-fashioned skeleton key. To gain access to the room, the two silver keys must be turned simultaneously to uncover the keyhole for the skeleton key. Once the skeleton key is turned, the door may be opened.
Warden James ' keys were in his possession while on Alcatraz in the early 1960's. James is more protective of these keys than the key(s) used to open the secret vault containing millions of dollars in gold bars. In 1960, inmates Herman and Edward Ames stole the silver Folger Adams keys from Warden James and made copies of them in their effort to gain access to the hidden gold. However, Warden James catches the two trying to gain access to the room where the gold is kept, informing the Ames brothers that they had copied the wrong key(s). James then confiscates the key copies.
In 2012, Jack Sylvane steals one of the Folger Adams keys from the residence of Barclay Flynn, and Cal Sweeney steals the other from a safety deposit box in a bank. Harlan Simmons , who was paroled off Alcatraz in 1960 and did not make "the jump" like the other inmates, was in possession of the skeleton key in 2012 until it was stolen by Garrett Stillman and subsequently by Joseph "Ghost" Limerick , another former inmate of Alcatraz. When Limerick commits suicide by jumping out of a third story window, Diego Soto finds the skeleton key sewn into Limerick's pant cuff and gives it to Hauser, who uses it to unlock a secret door beneath Alcatraz.