Someday

Hilda was crowned the Lost Unovan Champion for a reason. She was a powerful trainer, an honorable fighter, and a wonderful friend... until she vanished off the face of the Earth. She seemed to disappear without a trace. Eventually, Iris took her place as Unova's Champion, Cheren became a respected gym leader, and Bianca pursued a career in the science of pokemon. Even as life moved on, neither Hilda nor her legacy was ever forgotten.
Even after three long years, the string of fate and friendship has the trio firmly tied together. After a disturbing nightmare about Hilda, Bianca finally decides to take action. She, along with Cheren, Professor Juniper, and Hilda's melancholic mother must assist each other in embarking on one last journey: one last attempt to bring the Lost Champion home.