This Is What Happened by Mick Herron

When I bought This Is What Happened, a short standalone novel by Mick Herron (best known as the author of the excellent Slough House spy series) I had just finished a very long and desperately sad, Booker-shortlisted novel, so wanted something short and pacy as a contrast. This Is What Happened did the trick in that sense. The story moves very fast and is almost over before you know it - if anything, it felt a little rushed to me, and I would have liked a little more detail and back story here and there.

The book opens with a young woman, Maggie, sneaking to a forbidden floor of the high-security office block in whose post-room she's employed, armed only with a USB stick which is intended to install spyware on to the office's computer network. It's clear that she isn't a professional spook, and her nervousness is almost palpable. Maggie has been recruited for this task by MI5, we discover, because her role in the post-room gives her access to the whole building and her presence is less likely to arouse suspicion. But can Maggie, a lonely drifter with little sense of purpose and no discernible exceptional skills, carry out a task of national importance? If she gets it wrong, not only will she be in terrible danger, but the whole country's future could be at stake.

It's a far-fetched but gritty nail-biter of an opening, with all the trappings of a page-turning espionage novel. But is this really spy fiction? Or is it something different?

To keep this review spoiler-free I won't reveal any more than is encompassed in the blurb on the back of the book: this is a novel that starts as spy fiction and then rapidly evolves into a psychological thriller. The main character, Maggie, is oddly likeable. She's certainly infuriatingly naive, but in a way this almost stems from her loneliness - living in London without family or friends or a sense of purpose, it's easy to see why an apparently bright woman might be willing to get involved with the plan proposed to her by Harvey, the slightly down-at-heel agent who approaches her in her local park.

There are really three distinct parts to this short book - Maggie's unwise involvement in Harvey's espionage plot, the sinister aftermath in which things become increasingly dark, and the resolution. This is a lot to cram into what's barely more than a novella and while the dialogue is excellent and  Herron does an excellent job of establishing the settings and characters convincingly and quickly - as he does in the Slough House series - I felt the ending was overly hurried. At times, I felt as if I was reading the first draft of a longer novel.

That said, This Is What Happened is a quick and gripping book which makes full use of Herron's trademark combination of wry observation of slightly tatty locales and nailbiting tension - albeit perhaps not quite in the way you're led to expect from him.