I chose Siren's Call: A Dark Tides Novel by Devyn Quinn from the Q shelf so I can swoop on through the last letters of the Alphabet Challenge, but it was hard to finish. The romance was annoying in that the main obstacles between the characters were 1) they had no reason to like each other and 2) her ex boyfriend (whom everyone hated) shows up, so the new boyfriend sinks all his money into a partnership with him.
The writing had a bad habit of telling rather than showing, and often telling the opposite of what it was showing. I shall invent some lines to describe what I mean: "She looked at him uncertainly. Although she had never been comfortable with men, this one left her hesitant, unsure what she wanted to say or do. She said, 'Take off all your clothes so we can have sex right now.'"
To make matters more annoying, the science fiction aspects had me banging my head against any sturdy surface. She's a mermaid, he's a rich handyman, and her ex-boyfriend is a treacherous scientist, so they all join together in a archaeological dive looking for traces of mermaid civilization. She swims down to an ancient temple and accidentally summons the two men to this underwater site. No one worries how they are going to get the air-breathers out because obviously the most immediate concern is to start excavating what looks like a tomb but is actually a portal to the mermaid dimension. Sadly, the mermaids in that dimension are mostly mean types who want to take over our world with their super-powered magic ray guns. The only way to stop them seems to be for our heroine to cross back to the bad dimension, but that would interfere with her new wedding plans so it's not really an option. The end! D-.
On the other hand, my twelve year old quite liked it. He read from the discovery of the portal, because he came to ask why I was beating my head on the side of the car. He did have to skip the sex parts, but since they are completely divorced from anything happening to the plot or characters, that wasn't hard. (Oh no, they got thrown in a bare cell. Time to have sex for several pages before the mermaid can remember some more previously unmentioned powers.) He gave it a B.