Though Robards casts Shiver as a thriller, she cannot quite subdue her penchant for romance—even in the midst of terror. Usually I wouldn’t read this title, given the author’s reputation as a genre romance writer, but the plot is compelling enough to sustain interest, even with the heavy breathing between stunningly attractive characters.

There is little secrecy about the direction of the plot as it unfolds: an undercover FBI agent masquerades as a criminal in Witness Protection with the US Marshals as a brutal Mexican drug cartel (the Zetas) does their best to keep “Rick Marco” from testifying. Danny Paterro is so deep undercover that only a handful of FBI supervisors know the extent of his activities. The drama begins when twenty-three-year-old tow truck driver and single-mom Samantha Jones hooks up a BMW on her list of tows for the night.

Samantha is struggling to make ends meet. Four-year-old Tyler is home with a kindly neighbor babysitting as Sam braves the night and the cold to make a living. When she opens the trunk of the BMW and discovers a wounded man inside, Sam is ambushed and catapulted into the confined space with him. Through Sam’s ingenuity and quick instincts, the two manage to elude their captors in a narrow escape, though Marco refuses to cut Sam loose afterward, knowing their pursuers will track the tow truck back to Sam and her son.

What follows is a cat-and-mouse game between the killer Zetas, frustrated US Marshals, Marco and his reluctant companions, with Tyler snatched up along the way. The Zetas have indeed tracked Sam, prepared to eliminate any witnesses to their recent violence, including Tyler. Whatever confrontations exist in this thriller are life and death, take-no-prisoners encounters. The action starts when Samantha discovers Marco, after which there is no let up until the end. Sam fights both Marco and the marshals, trusting neither, but is by now deeply afraid of the brutal men in hot pursuit.

As his wounds heal and bruises disappear from the beating the Zetas gave him, the devastatingly handsome quarry and the black-haired beauty are literally thrown together frequently enough to make their physical attraction all but impossible to resist, danger creating the strangest of bedfellows. Even the “good guys” aren’t immune to corruption as Sam and Marco find themselves on the wrong end of the equation with the deadly and determined criminals, unsure if they can truly trust anyone to protect them. Though the romance gets hot and heavy, so does the danger—although happily ever after is the expectation, love intact through a rising body count, plucky Sam trusting the man she believes is a crook.