A Grave Undertaking
Sly, you'd better be on your guard here. My paranormal scanners show this place is really haunted!
― Bentley warning Sly about the dangers that await[src]
"A Grave Undertaking" is a job in "Vicious Voodoo" of Sly Cooper and the Thievius Raccoonus.
Synopsis
Bentley contacted Sly to warn him about how haunted the area was, as indicated by his paranormal scanners. As Sly pressed forward, he came across a gravestone that was continuously spawning ghost rats. Upon smashing it, the ghosts stopped appearing all of a sudden, leaving Bentley to believe it was some sort of ghost generator. By smashing them all, Sly would be able to make it through safely.
Clues
There are 40 clue bottles to collect in this level, and the vault is located behind a set of breakable sticks after defeating the last wave of ghosts. The vault's combination is 1-2-8.
Okay. Okay, this is kind of a guess, but try 1-2-8.
― Bentley[src]