Two friends go to St. Petersburg on a business trip that will change them forever. Completely different, like ice and fire, the guys equally fall in love with two Petersburgers. Reliable and pedantic Kostya loses his head when he meets the eccentric Ira. And freedom-loving womanizer Sanya first thinks about a real relationship, having met the mysterious cellist Nadia. Love turns the measured lives of Muscovites upside down - and none of them knows what to do with this new feeling.