It starts with the horrible murder by monster of four-year old Ethan's beloved big sister, which he sees happen. And then we jump to high school Ethan, still traumatized, with dysfunctional parents, and learn that Ethan was taken in by a society of guardians, who (with the help of a pantheon of mysterious deities who don't do much in terms of direct action) fight the forces of chaos trying to rip apart the past to make more chaos. So Ethan is one of the Named, as they are known, and he's doing well in his time travel missions, trained by a purple-eyed 600 quasi-magical dude....and he reaches the next step in guardian advancement--he assigned an apprentice.
(me reading--not yet sure I like the book)
And the new apprentice is his ex-best friends little sister, Isabel. So there are some real world problems, but Isabel takes to being one of the named like a fish to water, and it's clear to the guardians that Ethan and Isabel are part of an ancient prophecy, which, when we finally get to see what it says, is both confusing and somewhat pointless, and why did they have to make a difficult and dangerous journey to a magical underground chamber to read it when writing things down is a thing (? I could have missed the point, or possibly several points.)
But Ethan and Isabel also time travel, and I liked their missions (saving Richard II and young Abaigail Adams from the chaos operatives, including the sister killer monster, trying to snuff them). It's pretty easy time travel, where clothes and language and backstory problems are all taken care of (although I think they should have been sprinkled in grime instead of having new nice pretty clothes every time), but it was satisfying on the whole.
And then everything gets very existing as new characters from the real world are brought into play and there's a big show down with sister killing monster and his gang, and I was reading very vigorously.
So I guess I like the book (with the exception of the prophecy and Isabel's romantic yearnings for purple eyed, 600 year old dude, which moved me not at all), and I rated it four stars on Goodreads for keeping me up late. And I have the next two in the series, and they may well show up here some Tuesday in the future....But there's a lot of flashy premise and not quite enough careful subtlety of story and character development to make me want to reread it--I'm don't think I'd get more out of it a second time through, which is how I feel with a book I am certain I like.