Tom Clarke faces his greatest challenge yet, when a mysterious elevator takes him to Floor 13 – a destination leading far beyond this world. While Benny struggles to understand this ancient trap, the Nekross arrive, ready to feast – only to discover that Floor 13 has terrible plans for them too…
Trapped in a distant dangerous realm, Tom and Lexi must find ways to survive together – but is their friendship capable of becoming something more? While Benny summons Ursula to fight the gruesome Troll, Tom must do more than fight; he must become a man. But will the cost of returning to his old life be too great?
- The Thirteenth Floor was extremely well-received and was seen, by many fans, as the best story of the series. The story won a place on the Den of Geek website's top 15 TV episodes of the year, coming no. 11 and beating shows such as Arrow, Luther, Hannibal and Being Human.
- This story was originally planned to be the fifth story in the fifth series of The Sarah Jane Adventures but was never filmed due to the death of Elizabeth Sladen, the main actress. The script of the story was modified to fit in the world of Wizards Vs Aliens.
- Tom Clarke - Scott Haran
- Benny Sherwood - Percelle Ascott
- Ursula Crowe - Annette Badland
- Michael Clarke - Michael Higgs
- Varg - Jefferson Hall
- Lexi - Gwendoline Christie
- The Nekross King - Brian Blessed (voice)
- Jathro - Tom Bell
- Mervyn - Paul Putner
- Alicia Ferguson - Jessie Cave
- Elizabeth Hatcher - Jo Martin
- Old Elizabeth Hatcher - Sandra Scott
- Security Guard - Saikat Ahamed