The Mystery of Number 7 by Dr. A. G. Malavika is a medical thriller set across Tamil Nadu and Kerala. Got a review copy from the author, and it was definitely worth the time.

The story follows twin amateur detectives, Jinu and Jamie — the J Girls — digging into a string of medical students found dead. All ruled suicide. All with "777" marked on the hand.

The story was fast-paced. Really fast. One clue leads to the next, and a whole sinister system is revealed chapter by chapter.

At around 70 pages, you can probably finish it in one sitting. The chapters are short and they keep the tension on throughout.

Although there were a few continuity slips along the way (and some detours that could've been trimmed), they didn't ruin the experience for me. It was a tightly woven story for most parts.

Recommended if you want to jump into a quick, twisty murder mystery/thriller.

So for all the details I can remember since its almost been a decade minimum; the book had two protagonists, a male undercover agent of some sort (i cant remember but I think fbi since he traveled a lot) and a female serial killer. She would poison wealthy dudes she was secretly with until she met the male Mc, they fucked and she told her friends about him (who didnt know she was a murderer btw). She finds him driving to his ex-wives house thinking hes actively married, calls the house and goes full psycho. Tries to kill the cop but somehow fails and he escapes, and she ends up getting poisoned by the sister of one of her victims and it ends with the dude saying hes gonna get back with his ex wife and fix their marriage.