The sequel to The Strength of a Kiss, The Strength of a Promise begins in May 1967, when 17 year old Lauren's life changes forever. Her love for 25 year old David, who is married with a baby daughter, threatens to destroy everything she has ever known; splitting their families down the middle. They live in a small village community, and when David's mother-in-law discovers their affair, Lauren's sister and guardian has no choice but to forbid their relationship. To condone it would ruin Lauren's reputation; even though David's marriage is virtually over. During the next 18 months Lauren is forced to grow up in the cruelest possible way. Moving to Cambridge city with a friend, and estranged from her family, she attempts to put her life back together, while her sister Kay seizes every opportunity to drive Lauren and David further apart; finally betraying them unforgivably. When David is brutally attacked and left for dead, Lauren rushes home to be by his bedside, but soon discovers her actions have made matters worse. As Lauren's story continues she emerges from adolescence into womanhood with a bittersweet taste in her mouth. Heartbroken and away from home what are her chances of ever finding happiness?