[1] The series follows Henrietta "Hettie" Hubble (Mildred's younger cousin), through her years at Cackle's Academy.

Mildred is seen at the start of the first episode riding her cousin's broom close to Cackle's and she then disappears.

Hettie quickly becomes best friends with Mona Hallow (who happens to be Ethel's younger sister) and Crescentmoon "Cressie" Winterchild.

Hettie and her friends' new enemy is Belladonna Bindweed and her sidekick Cynthia Horrocks.

The New Worst Witch was initially planned to have a third season in 2007, but Alice Connor who played Henrietta Hubble in the series along with several other cast members decided not to sign onto the third season and thus was subsequently canceled the same year.