Is This a Mysterious Encounter?

is episode 1 of Magical Girl Lyrical Nanoha. It was originally broadcast on October 1, 2004.

Nanoha was just an ordinary third grader with no special skills when she heard a call for help. Then Nanoha comes to Yūno's rescue, and in doing so was given Raising Heart and awakened the power that had laid dormant inside of her.