Bridgehead
First we have a college, which is kind of appropriate seeing as how much trouble and problems are usually generated from those "higher centers of education. Research is being accomplished on time travel and assistance is being rendered by humans from the far distant future. but what if those humans and our far distant future - as well as our past - aren't as advertised? How about some chlorine breathing bugs with an advanced (also) technology who are fighting with our (time) travelers? Then, for dessert, consider if everything goes according to plans by the bugs and travelers, our Earth is a disposable chip from either sides point of view? A very interesting book by David Drake.