Two scientists unexpectedly stranded in a technological backwater find, to their dismay, that conservation of energy and e-mc² are in effect. Most of their technology is useless. They have two ways to get home: try and merge the reality they are in with the main causality, or rebuild a navigational database from readings taken across space and take a shortcut. Unfortunately co-operation could be a problem. The world they came from was at war, and they aren't on the same side, or even the same species.
Under a shaky truce, they explore a series of worlds where physics may not work the same way, aliens exist and may never have encountered their various species before, and most dangerous of all, places where life as they know it is not supported. Since most of their technology is unavailable, they only have their knowledge of logic and science to save themselves. Between these infrequent trips, they have to build their operations base without damaging technological progress - starting on 1920s earth, and one of them knows enough history to know that there's another war on the horizon...
Series & Genre:
The Killgrace stories are a series of SF and historical stories. The premise: what if a being that manipulated dimensions - height, breadth, depth and time - encountered one that manipulated forces - strong, weak, electro-magnetic and gravity?
The science, in general, is fairly hard. There are three basic conceits: the abilities of the main two leads, the idea there are multiple universes with different physical laws, and the idea people can travel between them. Everything else builds on the results of those.
The focus is mainly on science and possibilities, not the characters, and romance fans will be disappointed. (One of the leads is an energy being in a flesh suit. The other is a cartiliginous being in a metal one...) Ethics and implication is also something explored.
The stories can be read online free as individual serials or bought through Amazon or the site if you want to support the project.
Where to Start Reading:
The free short stories on the site, under Read Online are a good place to start. .
If you want to follow the historical timeline, Killgrace In Depression is the best entry point. Otherwise, Killgrace and the Alien Threat is their first hard science offworld trip.