This was your typical high-drama medical thriller, though it took me a while to figure out the relevance of the title because 'the fourth procedure' isn't explained until the last hundred or so pages, nor does Pottinger give readers many clues as to what the first 3 entailed.
The book focuses on Congressman Jack McLeod; his activist on-and-off girlfriend, Victoria; Supreme Court nominee Judge Abner Titus; plus a few other significant characters and some minor ones in what is largely a novel about pro-life Titus challenging the Roe v. Wade court ruling, while pro-choice McLeod sees first-hand the consequences of preventing legal abortions after the death of one of Victoria's clients, which strengthens his position even more. Running concurrently with this plotline is one in which abortion clinic bombers are found dead with autopsy incisions, missing livers, and toy babies in their abdomens.
On the back cover, the book synopsis first mentions surgeon Rachel Redpath, who is a colleague of Victoria's and also performed Titus' kidney transplant, and her being called to a life-saving surgery. I don't recall that particular plotline, unless it refers to Titus' transplant, which occurs before the events in the book. Redpath was the character I was most interested in following through the course of the story and she seemed largely ignored for much of the book, so I was a little disappointed, as McCloud was clearly the main focus of the novel.
Overall, I enjoyed the book, it just seemed to take a while to find its focus and move from the abortion debate to the procedures referenced in the title.