With the help of celestial cattle, Niulang flew to heaven with his son and daughter. When he was about to catch up with his wife, the Queen Mother took off one of her gold hairpins and scratched a river in the sky to separate the lovers. Niulang and Zhinü have been separated on the two banks ever since. Once a year all of the magpies in the world come to build a bridge for Niulang and Zhinü to meet each other. This meeting happens on the 7th day of the 7th lunar month. Because of this, their meeting is called "Qi Xi" (Double Seventh).