Thanks to her sister Susannah's destructive behavior, Grace feared pregnancy. However, in her thirties, she suddenly hears her biological clock ticking away. She and her husband Tom decide to have a child. Fourteen months later and a cost of a ton of pounds, Dr. Janus informs Grace she can never conceive. Because of Tom's heart defect, adoption is also out. Strategic thinker Grace plots her next child campaign even as she almost abducts a baby.
In America, Homeland Security informs Susannah that she will be sent back to Great Britain. Between ex husbands, alcohol, drugs, and sex with anyone even when she was married, Susannah knows arguing is futile. When their mother Catherine suffers a debilitating stroke that leaves her comatose, Grace demands Susannah come home, which she does. In Oxfordshire, Susannah becomes a surrogate mother for her sister, but though pregnant she still drinks and sleeps with everyone. As she tries clean up, Grace and Tom head to divorce court with custody becoming an issue.
This is an interesting look at two sisters whose lifestyles are dramatically different yet in many ways the same as each tends towards obsessiveness bordering on destructive compulsion. Numerous medical crises become a gimmicky conflict resolution technique that severely detracts from the family drama as does a bit of whimsy involving their mom. Still fans will wonder how much is too much sharing between sisters.