If the slew of terrific books published just a few weeks into the new year is any indication, readers are going to have a target-rich environment on which to focus their attention. If I may, please let me direct yours to Mick Herron’s latest effort. If you know that name, then you really don’t need to read any further. If not, then know that Herron is an oft-honored, critically acclaimed British author of thriller and espionage novels, each of them worthy of your time, attention and money. THIS IS WHAT HAPPENED sees Herron exceed his own lofty standards.

And now I have a bit of dilemma: How do I get you to read this wonderful book without including all sorts of spoilers? Let me try. Maggie Barnes is a 26-year-old living in London and working as a mailroom clerk. She is a shy underachiever, resentful of being in the shadow of her older, smarter and more accomplished --- and estranged --- sister, but is unable to do anything about it. When we meet Maggie at the very beginning of the book, she is hiding in a restroom of a restricted area in the building where she works. The reason is that she has been recruited as an agent of MI5 by a mysterious gentleman who introduces himself as Harvey Wells. It develops that there is a multinational corporation headquartered in Maggie’s building that MI5 is keeping tabs on, and the agency needs some eyes-on reports as to what is occurring. Maggie gets swept up in the reporting, which is exciting but safe.

"[T]he book has the potential to be the next big thing, like THE GIRL ON THE TRAIN next big thing.... It's an espionage novel, a thriller and a mystery, all rolled into one glorious book that you can and will read in one sitting..."

All of that changes when Wells asks her to perform a covert act of espionage after working hours, one that involves sneaking into the company’s offices and infecting its main computer with spyware. It goes well until it doesn’t. Maggie is almost discovered and barely escapes, but there are repercussions. Wells puts her in a safe house, but the operation, while ultimately a success, has some unintended consequences that result in Maggie being forced to remain hidden while London undergoes a sea change. Something, though, is not quite right. As things unravel, so does the relationship --- professional and personal --- between Wells and Maggie. Then a third party intercedes, and things get worse.

How much worse? And do they get better? Trust me, you want to read THIS IS WHAT HAPPENED to find out. I’m going to go out on a limb here and tell you that the book has the potential to be the next big thing, like THE GIRL ON THE TRAIN next big thing. Seriously. It’s an espionage novel, a thriller and a mystery, all rolled into one glorious book that you can and will read in one sitting, once you discover that the first half sets up the story and the second half makes you wonder how it’s all going to end…or if it’s going to end at all. All of it, by the way, is beautifully told in a semi-understated fashion with revelations big and small strategically placed to explode where and when you would least expect them.

Trust me on this: You need to read THIS IS WHAT HAPPENED before your friends do and spoil the ending (and the middle, and the beginning) for you.