You can read the full review (and experience all the fabulous gifs) on my blog: http://rlhendrian.blogspot.com/2015/0... 
 Forever Red starts in Ukraine, 8 years in the past (you can actually read the beginning online). The Black Widow is hunting down her old mentor/trainer, Ivan Somodorov. The mission goes south, but not before Natasha rescues the girl that Ivan was experimenting on, turns the girl over to S.H.I.E.L.D., promises she'll come if the girl needs her, and leaves. 
 8 years later, we are introduced to the primary characters (other than Natasha): teenagers Alex Manor and Ava Orlova. Ava is, of course, the little girl that Natasha rescued eight years earlier. Ava had been living in a (dreadful sounding) secure S.H.I.E.L.D. facility before she escaped, and she currently lives in the bottom of a Brooklyn YWCA. Both of them have strange dreams, but Ava's are about Alex (she's never met him). Ava has also nurtured hatred against the woman who saved her life, and then left her to fend for herself in a strange world. 
 But children are disappearing again, and the Black Widow suspects that Ivan survived their confrontation. That means he is after her, and after Ava, so Natasha heads back into the field, and back into Ava's life. However, things are far more tangled than Natasha realized: her memories are leaking into Ava's head, thanks to Ivan's experiments in "quantum entanglement." Ava absorbs Natasha's skills, and the Black Widow can't feel it. As frustrating as this is, it's also incredibly dangerous. They aren't the only Entangled pair that Ivan left behind. 
 To disentangle themselves, Ava and Natasha must find Ivan, face their childhoods, and go back to where it all began. And what does Alex Manor have to do with everything? 
 5 things that worked: 
 1. I loved the book's format. Each present-day chapter is followed by a S.H.I.E.L.D. Line-Of-Duty Death (L.O.D.D.) case document. They are interviews (often with Natasha) and other files that tie into several plot threads. I love how these were worked in to the story 
 2. Margaret Stohl does a great job with Natasha's character. She's the hard edged, sensible, and capable assassin/spy we all love, but she's also human (but with a very messed up past). 
 3. Ava and Alex were both likable (surprisingly so), and I was interested in their character arcs. Ava as Natasha's "mini-me" provided some humor and insight into the Black Widow. 
 4. The plot. It was old-school spy stuff with gadgets, disguises, mad scientists, and chase scenes, but with an awesome heroine instead of a suave, suit wearing James Bond type. 
 5. The covert peeks into Natasha's classified past. Black Widow is mysterious, and that's one of the things I always liked. I was worried that a novelization would take away too much of that mystery, but it didn't. Natasha is given just enough history, just enough name-dropping (I didn't grin stupidly at everyone in the airport when I read a certain case note**), to both reconcile her comic/cinematic character, and leave a lot of interesting openings. Oh, and Coulson is in there a bit :) 
 BONUS: The Russian. I never forgot that I was reading about Russian characters, and it gave both realism and grounding to a book with a crazy mind-meld plot. 
 5 things that didn't work as well: 
 1. While I liked Ava and Alex, and was rooting for them, but they weren't why I was reading the book. I just didn't care as much, and I was far more engaged when Natasha was on the scene. 
 2. This was a minor part of the book, but the predictable Alex/Ava romance (while believable) didn't do anything for me. Sure, they were cute and not annoying, but (see above), I didn't really care. But hey, they're kids. 
 3. I felt like it occasionally suffered from trying to be too cryptic and mysterious. There were a few details that needed further explanation/examination for the plot's sake. The only major example of this was all the disappearing children.*** 
 4. Ivan. He had a bit of Marvel Movie Villain Syndrome: Ivan was evil, sadistic, and had quite the past, and yet he felt a little flat. But again, only Loki and Wilson Fisk (Daredevil) have truly escaped this.**** 
 5. This one is 50/50 for me (because sometimes it worked better than others): the constant reminders that we are in a very normal, modern, but alternate Earth where superheroes are an acknowledged thing and Avengers destroyed/saved New York once. 
 Overall: 4 out of 5 Spiders. 
 Footnotes: 
 *I know that having time and making time are directly related. 
 **(not really a spoiler but just to be safe) Black Widow's file has her age redacted. And there is a footnote that says to reference the files of Rogers, Steve and Barnes, James. Which means that they haven't thrown out her backstory from the comics. There is still a chance that Natasha will be more like her real age (just rewritten every time) and has trained under the Winter Soldier. So I grinned at strangers ( I was reading in a busy airport, people). 
 ***Seriously, where did all those kids go? If this was really addressed in the book, I must have missed it. I think it was just mentioned in passing toward the end. 
 ****If you count the Winter Soldier as a villain [which in CA:TWS he technically is), then that makes three.