In the Star Wars: The Clone Wars episode "Brothers", Savage Opress travels to the planet Lotho Minor in search of his long-lost brother. He's guided by an amulet given to him by Mother Talzin, that glows brighter the closer he is to his brother.
On three separate occasions, the amulet temporarily stops glowing: once while he is flying over Lotho Minor, once shortly after he lands, and once shortly after he enters the entrance to his brother's lair. On the third occasion, Savage believes Mother Talzin has betrayed him, but once he enters the depths of the lair, the amulet starts glowing again, and sure enough, he finds his brother alive.
While it's hard to tell with Mother Talzin, I don't believe she betrayed Savage (if she did, the amulet wouldn't have turned back on again). But that begs the question: why did it keep going out? Was its magic running dry? Was it like a "you have reached your destination" thing? What was going on there?