What is the main conflict in The Slippery Slope by Lemony Snicket?

"The Slippery Slope" is the tenth installment of the "Series of Unfortunate Events" series of books. It relates another episode in the adventure of the Baudelaire children, Violet, Klaus, and Sunny, in their attemps to escape the evil Count Olaf, who wishes to steal the fortune left to the children after the death of their parents in a house fire.