Alison and Daniel fall in love in 1989 Sheffield, but Alison runs away despite their strong connection. The story hints at family anguish, poverty, and changing times as the backdrop, suggesting complex personal and social pressures influenced her decision, though the exact reasons unfold through the series' plot development.

Daniel and Alison reconnect decades later through shared musical memories, specifically by sending each other songs that remind them of their first love, effectively starting a new 'mix tape' that rekindles their connection despite Daniel living in Sheffield and Alison in Sydney.

As an adult, Alison has a seemingly perfect life as an author in Sydney but carries a lot of trauma from her past. She has written a book to branch out of herself and struggles to keep a lid on her feelings, navigating many challenging emotional and personal issues throughout the series.

Daniel remains in Sheffield, living a stable, predictable life as a freelance music critic. He married Katja and has a son, but his past with Alison continues to affect him, especially as they reconnect. His family life contrasts with his unresolved feelings for Alison, adding complexity to his character arc.

Although Daniel and Alison initially believe they are not breaking any rules reconnecting through music, one of them does something that dramatically changes everything. This pivotal event is a key plot element that drives the tension and drama in the story, though specific details are revealed as the series progresses.