Secret Genius

The next 12 contestants face a fresh set of challenges based on the games Mensa use to measure IQ, including a code-breaking challenge so complex that the youngest contestant, student Rosie, really struggles with - and not just because she may never have seen a landline phone before. By the end of the episode, only three will earn a coveted place in the Oxford finals.

Alan Carr and Susie Dent host the final heat, with 12 more contestants competing for the last three slots in the finals. They must take on a physical anagram grid where contestants stand in the middle to become the missing letter, a twist on Guess Who? featuring pictures of cats and dogs dressed in regalia, and a bamboozling clock conundrum.

The final 12 players are faced with a high-pressure quickfire round, where they must solve a complex maths game to work their way out of a maze. After some surprising drop-outs, the remaining players face each other in a mind-bending memory game based on the periodic table.

Alan Carr and Susie Dent host the grand final. The four remaining contestants must place famous geniuses correctly on a giant board, before two are chosen to face the final challenge - a nail-biting second round of fluid reasoning and memory games.