u/Equivalent_Target_94

Heya! I remember reading this sort of futuristic novel around 2012 - 2014. It might be from earlier though. A group of scientists build/encounter a time travel machine. They travel underwater(??) and meet a race of pale people underwater.

They have to disinfect in a room, I think they shower, before entering the city. They are monitored. Then they mess up and kill a person and run away back to the machine. The people revenge and the scientists find themselves in another time.

I would really love to read this again.