S3, EP18 "I Dreamed a Dream?"
When an encounter with the Whispering Evil leaves Macy on the brink of death, Mel and Maggie cast an ancient spell, sending the Charmed Ones off on a series of epic adventures; Harry asks Jordan and Celeste to help him do the unthinkable.
S3, EP17 "The Storm Before the Calm"
The sisters confront the Whispering Evil, even though their collective powers may not be strong enough to defeat it; Macy must face down Abby's mother in order to acquire a secret weapon.
S3, EP16 "What to Expect When You're Expecting the Apocalypse"
The sisters must track down the Whispering Evil in the present to save the future; Harry fears his mortality journey may change him.