One Perfect Couple by Ruth Ware

AND THEN THERE WERE NONE meets THE TRAITORS

Five beautiful couples.
One deadly game.
Who will escape alive?

Lyla Santiago has spent months working on a research project that could be the key to getting a permanent job in her field.
So, she can't really drop everything to go to a desert island with her actor boyfriend Nico to film One Perfect Couple, a new reality TV show that Nico is sure will lead to his big break - can she?

Two weeks later, Lyla finds herself boarding a boat to an isolated luxury resort in the Indian Ocean.

The rules of the game are simple. Ten strangers have to survive together on the island - and the last couple standing scoops the prize.
There will be sun, sea, laughs and plenty of flirting.
What could possibly go wrong?

But when a huge tropical storm cuts them off from everything, the group must band together.
As tensions run high and fresh water runs low, Lyla realises that someone is playing this game for real - and they'll stop at nothing to win.

Ten might have arrived, but who will survive to the end?