Echo knows this is the snake car. She has avoided the snake car because there are snakes in the snake car. In an ideal world, she would continue avoiding the snake car that contains snakes inside.

And yet she cannot ignore the pleas of someone calling for help. Horny for heroism (or just without something better to do) she opens the snake door that leads to the snake car. There are snakes inside. But, more concerningly, a Quackenbush.

"Where are the other two?" she asks, expecting their siblings to reveal they're trapped inside the crates.