But what's your time worth?
The novel starts out by getting bogged down in a lot of description of things you'll never see again. It follows some characters caught up in the opening salvos of a Civil War battle--and a drive-by shooting--without bothering to make any further use of them in the rest of the novel.
The reader is also subjected to a step-by-step description of how one amputates a limb. Not exactly fun for the squeamish nor does it add anything except gratuitous gore. It's almost as if the author flunked out of medical school and then consoled himself by reciting his anatomy lessons. That's not fair, I've no idea whether the author flunked anything medical.
The indie writer who forgoes the expense of editors and proof-readers not only makes himself look like an ignoramus, but he also tarnishes the reputation of every other indie writer. I'm not saying that I never confuse "lay" with "lie," or "who" with "whom," but I do spend good money hiring people to vet my prose for such.
Then there is POV. It stands for "Point Of View" and if you don't know what that means, you don't have any business writing in this century. A well-disciplined writer picks one POV character and he projects the entire story onto the perceptions of that individual. This isn't always easy in a story where you have multiple story threads. Or when you kill off the POV character. (Though William Holden did a fairly good job of sustaining the narrative after his demise in Sunset Boulevard.)
Our time traveler changes time thereby shortening the length of the Civil War by a few years. But he does so by the most obvious of actions. Anyone who's thought seriously about the butterfly-effect knows that teeny changes will have huge, unforeseeable consequences. In my stories I cite some chaos theoretic hocus pocus (strange attractors) to get around this, so I expect some subtlety.
Finally, there is the dreaded Mary Sue, or in this story Marty Sue. Our time traveler gets all the other doctors nearby to adopt his strange 21st century surgical techniques. He is made an instant Lieutenant, and then an instant Captain, and then an instant General without any of those pesky details of enlistment papers, sworn oaths, et cetera, et cetera, et cetera.
And if the gubmint found out some random surgeon was bopping back and forth in time, he'd end his days in that warehouse at the end of Raiders' of the Lost Ark.
All told, I cannot in good conscience give more than 3 stars to Tear In Time. It deserves less for the bad editing, but the story does manage to hold one's interest.