This is Carl's Brain
Top 15 Fantasy and Horror Novels: #2 Lightning by Dean Koontz

Lightning is a novel that has it all.  It’s  both mysterious and suspenseful, dramatic yet fully satisfying, and chocked full of well-developed characters.  The main character in the novel, Laura Shane, is a writer who has escaped some truly tough spots with the help of a guardian angel.  Except the guardian angel is no angel at all, but a World War II nazi.  Her guardian angel has always been there throughout Laura’s charmed life, and then one day he shows up at her front door in desperate trouble, being hunted down by the masters he once served.

The fact that time travel came into play came as an unexpected surprise, just as many of the other twists and turns found in this novel.  When Dean Koontz is on, he is one of the best suspense/horror writers around.  That is clearly the case here in this spellbinding tale.   The turning point in the novel is when Laura’s guardian angel shows up in need of help.  From there it goes from being an intriguing mystery to a fast paced thriller, skillfully handled by Koontz.  Lightning is one of the best written, most fantastic stories I’ve ever read.