Close up she saw two things: she knew who he was, and he was dead. Stewart Blake was a former schoolteacher, a convicted paedophile and murderer of a twelve-year-old girl, and his photo has been all over the news since his recent release from jail. Now his mouth hung open, and his pupils were fixed and dilated. The back and left side of his head were beaten in and dark blood pooled around him. Someone had taken their revenge.

The Darkest Hour is the follow up to Katherine Howell's superb debut thriller Frantic and succeeds in maintaining the momentum that was initiated with the first book. Returning is homicide detective Ella Marconi but she is one half of this dual protagonist story. In a rarity for crime novels, The Darkest Hour features two strong female lead characters with paramedic Lauren Yates filling the other role.

As can be seen by the above quote, Lauren Yates finds herself in a dicey situation late at night while working a solo shift. She spots two men sprinting out of a dark alley, one of them is injured and, while refusing her offer of medical attention, alerts her to the fact that there's someone else in the alley who needs her. She checks it out and finds a known paedophile lying there, dead. But she also finds Thomas Werner there, too. Thomas happens to be her sister's ex-boyfriend and father of her niece, but he's a violent man and warns Lauren to say nothing about seeing him there, adding a threat that he will come back and harm Lauren and her family if she doesn't do as she's told. Scared to death, Lauren says nothing.

A few months later Lauren and her partner, Joe, are called to a stabbing that took place in broad daylight in the middle of Edgecliff near Sydney's inner city. As the man is being rushed to hospital he reveals to Lauren that he knew his assailant and names him...it was Thomas Werner.

Remembering the threat Werner issued before, Lauren is torn. Does she tell the police or doesn't she? Should she risk her career by lying about the fact that she knows a man named Thomas Werner?

Ella Marconi has recently been appointed to Homicide and is desperate to prove that she is a solid detective, capable in her new role. The stabbing looks as though it could be the case she's hoping for, with an identification from a dying man and corroboration from a reliable emergency worker it seems as though this case should be a straightforward affair.

But when Lauren tells Ella that she wants to change her statement - that she thinks she may have been mistaken about what the man said - the case no longer looks as rock solid as it first did.

Naturally, Ella suspects the truth behind Lauren's reticence but it throws up many more complications she could do without. Then more bodies begin to turn up and the investigation begins to get very complicated.

Importantly to the success of the book, The Darkest Hour sits on a thoroughly absorbing plot but it's the character development that gives the story substance. We are introduced further into Ella Marconi's life during the course of the book and gain a deeper understanding of the pressures she faces other than her work. Equally, the complex emotional jungle that tangles Lauren Yates' life ensures that the reader takes a stake in her welfare and cares about how she is treated in adverse circumstances.

Like Frantic, The Darkest Hour showcases paramedic procedure to a nicety focusing a significant portion of the story on the desperate emergencies handled by ambulance crews. Again, the ambulance station at the centre of the story is located at The Rocks in Sydney. Howell's expertise as a former paramedic is used to great advantage with the procedure and dialogue firing off with a sharp crispness.

Katherine Howell has again combined a solid police procedural thriller with the adrenaline-charged uncertainty of a paramedic's daily life. This is novel that exudes strength as a quality crime thriller, it's emotion charged action and relentlessly fast paced.