Michael Robotham continues his 'almost-series' with a 3rd thriller that simply reeks class. The Night Ferry thrusts the reader into the grim dark world of people smuggling and adds a further horror the spectre of an organised gang of baby peddlers operating throughout Europe. It's a confronting story that compels you to keep reading with a plot that hooks you early and then slowly tightens its grip until, whenever you put the book down you almost experience withdrawal symptoms.

So what's an 'almost-series'? Well Michael Robotham has circumvented the only drawback that a series has where the characters become jaded and stale to the reader. Instead he has taken one of the bit players in each of his books and then cast them as the lead protagonist in the next. Simple but highly effective with an undeniable freshness brought to each book as we become acquainted with a new lead while still enjoying the comfort of returning to familiar surroundings.

In this case we are introduced to Detective Constable Alisha Barba, an Indian of Sikh heritage who grew up in London's East End, a combination that has ingrained a strong survival instinct into her. She first made an appearance in Lost when she worked as Detective Inspector Vincent Ruiz's driver. She takes over from Ruiz who was introduced in Robotham's first book The Suspect which was led by Joe O'Loughlin. In just a few short sentences we are reminded of who Alisha is before carrying on into a more detailed description that allows us to become fully acquainted.

When Alisha Barba prepares to attend her high-school reunion, she has no inkling that her life is about to be irretrievably altered. The only reason she's going is because her former best friend, Cate, with whom she had fallen out in dramatic circumstances 8 years ago has asked that she attend. By the time the night has ended Cate will be mown down by a car and the most stunning of secrets will have been revealed.

But for every shocking revelation there will be an accompanying mystery. Ali is left to ponder the words uttered by the 8 months pregnant Cate to her during the only chance they had to be alone together: "They want to take my baby. They can't. You have to stop them..."

Motivated by feelings of guilt at having already let her friend down once in her life, Ali vows to get to the bottom of the circumstances that led to Cate's accident. Some sort of illegal surrogacy program lies behind Cate's secrets but the full extent is still unclear. It's not until Ali is summoned to the English docks and to the tragic result of a people smuggling attempt that the full realisation of just what she's up against hits her. Her name and address are sewn into the lining of the clothes of one of the refugees which compels her to set her sights on the origin of his journey, leading her to Amsterdam.

Apart from an eye-opening tour through Amsterdam's red-light district Ali, with more than a little help from her retired former boss Vincent Ruiz, uncovers a highly organised baby brokering operation. High organised, highly illegal and very lucrative...and very motivated to guarding their cash cows. Trying to find out who is behind it all is not only going to prove extremely difficult but also extremely dangerous.

Ali is initially motivated by a sense of obligation but this soon grows to a more personal outrage as she uncovers the true circumstances behind her friend's pregnancy. The stakes are raised so that this becomes a lot more than a straightforward police investigation and she is driven by her own values, putting her job at risk, her relationship on the line and ultimately her life in danger. Emotional and moral issues are at stake, as are human lives. Past sins long since forgotten are revealed again and have festered to come out even angrier so that they will play a big part in directing the course of events.

The Night Ferry is about making up for lost time, about mulling over just how far one should go to have a baby before it becomes a morally reprehensible act. Robotham makes you care about his characters by giving them soul, making them personable and making them fallible. Behind the tough cop exterior that Ali presents to the world lies a compassionate woman who begins as only vaguely aware of the things missing in her life. This is a journey of self-discovery as much as it is an outstanding and moving thriller.

The Night Ferry is a thriller of tremendous depth and a triumph of emotion. There is a significant nod to cultural diversity which widens the story's appeal thanks to Ali's Sikh heritage and the broadening of the setting to The Netherlands. It all adds up to an outstanding story that succeeds in making you think long and hard about the essential difference between legally right versus morally right.