Inner city school teacher and would-be song-writer Mark is fairly happy with his hedonistic lifestyle. His pupils are proving a trial beyond endurance in his attempts to put on a school production of Cabaret; the football teams' performances are woeful beyond description; his song-writing has stalled. But he has his tennis, his temporary paramour Stella and the two other women in the Gang of Six. He probably would have stayed mired in his purposeless life had not his sister died from an overdose obtained from the drugs den frequented by the Gang of Six. Returning to the scene after the funeral he goes in search of the supplier, Ziggie, only to encounter and immediately fall in love at first sight with Madeleine. He abandons his hunt for revenge in favour of the only woman he has ever cherished.

For almost a year it seems that Lady Luck is on his side. Maddy moves in and shares her singing career with him. He introduces her to the London he loves. He takes her to see his parents in Liverpool who dote on her. He is ready to settle down, marry and become what he has most avoided in his life, a responsible adult.

Just as life seems perfect Maddy returns early from a gig to tell him she's pregnant, only to discover him with a naked pupil, and their relationship appears over. She has her flight booked and is on her way back to her native Australia. He now has five hours to get to Heathrow to argue her out of leaving. It should take eighty-one minutes using the London Underground Piccadilly Line. But the Piccadilly Line is in meltdown, suffering every delay and obstruction known to humankind, plus a few it has just invented that day.

While Mark sits and fumes in frustration he writes notes to his unborn child, "Danny", promising him or her that he will somehow get there on time and prevent YBM (Your Bloody Mother) from leaving his life forever. As the stations go by and red signal is followed by security alert is followed by termination due to late running he begins to realise that time is running out and his chances of reaching Heathrow in time have now, like his relationship with Maddy, dropped to below zero.