Spider's Trap by Jennifer Estep

While attempting to untangle a dispute between a pair of minor mob bosses at a meeting hosted on her friend's riverboat, Gin - now the reluctant leader of the Ashland underworld - contends with more of a blowup than anticipated when a mysterious stranger detonates a bomb on the boat. It takes Gin a while to determine who the real target of the attack was, and when she does, it brings back flashbacks aplenty from her days training with Fletcher.

As has become the routine in these tales, Gin doesn't really want to get too involved in pursuing the attacker until one of her friends gets hurt. In this case, it's bf Owen, who narrowly escapes death at the hands of a vengeance-minded metal elemental.

Ok, so I've wondered occasionally why the all powerful and all knowing assassin, the Spider, with all of her friends and resources, never seems to spend any time just thinking about her craft, and how to do things better. It seems like she was more effective in the earlier stories, actually.

One of the key plot devices in most of the conflicts is the use of elemental magic. Why don't any of her allies sit her down and just do a brainstorming session about what possible attacks and defenses a fire elemental, ice elemental, stone elemental, metal elemental, water elemental (you get the drift?) would be most likely to use, or have been seen to have used, let alone come up with some novel ideas for how to attack or defend against one? Fletcher was supposed to have been one of the most feared and respected assassins in the history of Ashland, and Gin has access to all of his files, but he never wrote down anything he had learned about how to kill elementals? If he kept files at all, they ought to have been useful stuff, right, not just gossip and reminiscences. Of course, in the first place, what self-respecting assassin would ever keep paper files laying around his home for anyone to stumble across. Really?

So, once again, Gin gets surprised by how tricky and powerful and nasty her latest foe turns out to be, and nearly dies several times, before finally doing something desperate enough to work.

Time for Gin to step up her game.