In the second semi-final, two more of last week's winning families return to the games lab and go head to head in the ultimate test of intelligence in a bid to make it through to the final.

Tonight is the grand final of The Family Brain Games tournament and the three sharpest families are attempting the final super-charged challenges with ultimate levels of difficulty. They play two cognitive challenges, followed by a further round of the fiendishly difficult Interrogation game. We say goodbye to one family, leaving the remaining two families in direct competition for the final as they go head to head in The Ultimate Brain Game.

With the stakes never higher, who will triumph and be crowned the winner, taking home The Family Brain Games 2019 trophy?