Wilson and the group traveled to Berkeley, California, where her friend, Sue Ennis, was studying to receive a PhD at the University of California, Berkeley. Ennis became a writing partner on the group's fourth release, "Dog & Butterfly", which they wrote together over the course of a single day. The album was released in October 1978, selling a million copies within the first month. It remained on the album charts for the better part of a year and went on to become a triple-platinum album. It was the band's fourth million-selling album in a row.