The One is the fourty-fifth episode of Ben 10: Universal Road Trip.
Ben, Rook, Charmcaster, Helen and Pierce enter the Temple of the Four Elements, where he has to undergo 4 trials in order for Ben to become a Spellbinder. While Grandpa Max challenges him to go for a day without going Alien for his trials.
- Having completed the 4 trials, Ben is now a Spellbinder
- Ben discovers his Spellbinder bloodline is related to the Great Houdini, and that there is Chinese in him from Fa Mulan in his ancestry, which meant during the colonization of America intertwined the bloodline.
- Ben Tennyson
- Rook Blonko
- Gwendolyn Tennyson/Charmcaster
- Helen Wheels
- Pierce Wheels
- Max Tennyson
- The Elementals:
- Tola Narnia: Fire Elemental and leader of the four Elementals
- Ramhorn Growl: Air Elemental
- Mongor: Earth Elemental
- Mandarain: Water Elemental
Tola Narnia: Ben there will be no Aliens, this task is for you and you alone.
- There are mentions of Eric the Spellbinder completing his training there, as well as Urich (6th century) from Scotland, Reginald (7th century) from England, Opar (8th century) from Egypt, Star Bear 9th century) from Algonquin Tribe, Mathias (10th century) from Israel, Morgana (11th century) from Ireland, Lionel (12th century) from France, Carolinus (13th century) from Flight of Dragons, Korso (14th century) from Russia, Fa Mulan (15th century) from Disney’s Mulan, Kirkland Oglethorpe (16th century) from Germany/Pied Piper, Tobias Grant (17th century) from Texas, Gertrude Vanessa (18th century) from Belgium, The Great Houdini (19th century) and Peter Dickensen (20th century) from Flight of Dragons, who all make cameos during the flashbacks.
- This is the first episode where Ben does not use any Aliens.