A common version of her story is that Apollo gave her the power of prophecy in order to seduce her, but when she refused, he spat into her mouth cursing her never to be believed. In an alternative version, she fell asleep in a temple, and snakes licked (or whispered in) her ears so that she was able to hear the future. According to legend, Cassandra had instructed her twin brother Helenus in the power of prophecy for him to be a prophet. Like her, Helenus was always correct whenever he had made his predictions; but unlike his sister, people believed him.