Who doesn't love a good amnesia story, especially when the person with the amnesia is an incredibly interesting and potentially dangerous person? Yes, it's a slightly cheap tactic to introduce the audience to the character's life, but it's also very effective in building suspense. 
 And Kristen Lippert-Martin puts it to good use in "Tabula Rasa," where the heroine lives up to that description -- she's a blank slate who has to discover who she is, what has happened in her pastand why some very nasty people are hunting her. Think "The Bourne Identity" crossed with "The Hunger Games." Kristen Lippert-Martin excels at writing in in a breakneck style crammed with action and fighting... but she seems less comfortable writing the quieter scenes of buildup. 
 Sara is one of a few kids who are blank slates -- they live in a remote sealed-off facility, guarded by staff round the clock. An experimental brain surgery has left them with no memories of their pasts; Sara doesn't even know what she looks like unless another kid tells her. But everything changes when she's left a pass-card and a bag of pills that begin to restore fragments of memory, allowing her to plot an escape... just in time for a bunch of armed thugs to storm the facility and kill everyone inside. 
 Her only ally is a mysterious young man, Thomas, who works for a legendary hacker known as 8-Bit -- and after seeing a tattoo on Sara's back, he identifies her as the wall-climbing rebel known as "Angel." And as Sara slowly gets memories of her life back, she begins to suspect she was more than just an ordinary urban Robin Hood. After all, why would a simple troublemaker be sent to such a place? 
 Unfortunately, in the present she and Thomas are struggling to remain undiscovered in the unforgiving, icy-cold wasteland of the US/Canadian border, with murderous shock troops, teen psychopaths and hallucinating soldiers roaming around. And to keep her mind intact, Sara must break back into the facility that was once her prison -- and rediscover the reason the malevolent Hodges and her billionaire boss Erskine Claymore have been trying to silence her. 
 "Tabula Rasa" is effectively a mystery -- but instead of properly solving a mysterious crime, the protagonist has to uncover the secrets she already knows, and the answers that are locked away in her own skull. It's also in the perfect setting for a gritty action thriller (a snowy northern wasteland a hundred miles from civilization), and Lippert-Martin weaves a tightly-plotted, gritty story full of explosive violence (including lots of guns and the occasional overturned trailer) and a sensation of creeping unease that never lets up. 
 And it doesn't hurt that Sara is a genuinely awesome heroine -- despite her helpless state at the beginning, she quickly shifts into a swift, ruthless tiger who is a completely plausible rebel figure. She's quick-thinking, smart, and able to adapt quickly whenever she's seemingly cornered ("I have the home-field advantage now. These soldiers--they're on my turf"). She's something of a contrast to Thomas, a hacker with a wealthy background and a rather surprising connection to one of the other characters -- he's a softer, less wild presence, despite his own tragedies and extralegal activities. 
 The biggest problem is that Lippert-Martin is still rather clumsy at writing strong emotions and quieter scenes. For instance, the early scenes where Sara is a prisoner in the facility should be murkier and more confused, yet she comes across as very clear-headed and observant despite her missing memories. Her terse, lean writing style also comes across as awkward and curt during these scenes, when they could have used a bit more passion and depth. 
 No, where she excels is the action and hard-nosed thriller parts of the story, delving into the grimier, grittier parts of Sara's journey. Playing dead, hiding in a long-abandoned trailer with rotted food, grappling with a psychopathic street tough -- these are all handled far better. And her prose style excels here as well, giving the speed and nimbleness that action scenes and sharp dialogue require. 
 "Tabula Rasa" is anything but a blank slate -- it's a pretty good thriller wrapped in threads of mystery, hampered only by the more contemplative scenes. Lean, exciting and pretty well-written.