In a test of their engineering skills, teams must construct a bridge across a 2m canyon with no centre support; the winning structure will be the one to withstand the most weight. With 10 hours on the clock, the race is on.

Three teams battle it out in the grand finale. With 28 hours to build, they can now create their ultimate masterpiece. Judged by public vote, Brickman and a top Lego designer.

Teams must duplicate the classic DeLorean car from Back to the Future - the real thing present for reference. Next, they re-create an iconic moment in cinema in a vignette on their tables, with the least impressive team saying farewell.

The four remaining teams each contribute to a Time Train diorama built in 16 hours. From the Wild West, the Future, Prehistoric and Medieval Times, this challenge will mark the end of one team's journey and reveal our grand finalists.

In the first elimination, teams must turn everyday items that have been cut in half from normal to incredible. A bike, a typewriter, a TV and a violin must be morphed into something completely new using only Lego.

The first challenge involves teams having to complete a LEGO City by filling in these empty blocks of land. They were given 15 hours to complete the challenge.

Teams have seven hours to make an amazing space-themed creation, but they will be judged on how spectacularly it breaks when destroyed by various means: baseball bat, high-speed crash, 6m drop or explosives.

Imaginations are let loose in this challenge where teams must create an evil lair for a supervillain Minifigure in 13 hours, including a vehicle. The least impressive villain world will ultimately send its makers home.

Teams must break apart Brickman's parrot to create something original in four hours. They'll then build an impressive three-storey apartment in 10 hours, stacking on top of each other's.