Jackpot, Sly! Look at all this stuff! Must be worth millions! And you know what that means... tighter security. You're going to have to be extra sneaky to get the treasure key here.
― Bentley advising Sly to be sneaky[src]
Sly entered into Raleigh's personal quarters, where the frog stashed a bunch of expensive items. With items at such great value, the area was heavily secured with lasers and spotlights. Sly had to be extra sneaky if he wanted to swipe another treasure key.
Whoever thought this code up knew what they were doing. Dial in 4-3-6.