Common Wealth - Álex de la Iglesia

Julia finds 300 million pesetas hidden in a dead man's house while selling an apartment. She's a 40-ish real estate agent now forced to face the wrath of a very peculiar community (of neighbors), headed by an unscrupulous administrator. Black humor gives way to suspense, closely followed by horror that doesn't take long in coming to a head in undisguised pandemonium.