Based on

Movies like Crash (2004)

A group of four people are seen working together on a structure made of blocks. An interloper joins their group, but can't conform to their procedures. She disrupts their activity, eventually damaging their work. A variety of tactics are employed in an effort to reform her into a productive member of their society. It seems to work and she becomes a team player. But, her seeming conformity triggers a reversal as the others see their own behavior reflected in hers. They act out destroying their own work, they lose their will and ability to function - they crash. Their shut down reveals her to be an agent of change, her actions a subterfuge.