The book of the TV show, ELEMENTARY: THE GHOST LINE is based around the characters of Sherlock Holmes and his sidekick Joan Watson. Set in New York, and having never seen the show, it seems that likely that the TV show is a reworking of the recent English reboot of Sherlock. Which probably raises the biggest question in my mind... Why?
Anyway, back to the book, which is undeniably engagingly written. Catching a lot of the colour and movement from the rebooted Sherlock (the one I've actually seen with Benedict Cumberbatch in it), there's high energy and high risk in this story. There's nice puzzle elements built into the overall plot of the stash of money, and Colombian connections, combined with what seemed like a nicely done evocation of hidden New York, in particular a network of tunnels underneath it.
The twist of a female Watson is carried off as well as you could hope for, with nothing seemingly out of place about the relationship you'd expect from two working colleagues, despite some fem-jep which made my teeth grind. The biggest problem is possibly that without ever having seen the TV series it's almost impossible to tell if the written version of the characters is true to the TV version. Of themselves they were okay, with Sherlock having enough foibles to make him seem at least sympathetic to the original and/or the English rebooted version.
Whether or not any literary companion to a rebooted Sherlock Holmes would work for diehard fans of the original is another question altogether. Taking ELEMENTARY: THE GHOST LINE in "standalone mode" for want of a better term, it's an entertaining read, with pace and a good plot. Even if, like this reader, you've never seen this version of the TV show, if you're a fan of a bit of swaggering action and logical concluding, it could work for you. If you're a fan of the reworked, reboot, it would likely be an even better read - as you've already dealt with the obvious twists on the original.