In a matter of just two weeks, Donald Trump is returning to the White House, and he’s bringing with him the world's richest man, Elon Musk. The Tesla and SpaceX CEO won’t just be an adviser; he’ll be at the centre of Trump’s administration, heading a new department: D.O.G.E.-the Department of Government Efficiency. But the question that the world wants to know is just how much power will Musk wield, and what happens if his vast business empire collides with Washington’s policies?