The coloring on the initial pages is actually pretty bad, even bubbles that were made harder to read. Time travel even in the best of times is annoying and tedious, this lazy setup... meh. Not really interested.
So there was a classified ad recruiting time travelers? Missed a step not including the "Must bring your own weapons. I have only done this once before. Safety not guaranteed" bit.
I was ready to drop this after the first two chapters because it felt like it'd end up as a bland high school slice of life. Very glad I gave ch. 3 a chance nonetheles, to see the premise getting more important.
How many pages does that time travel guidebook devote to the subject of killing Hitler? What about your grandfather? Any word on butterflies? Inquiring minds want to know!
At first, I've been with Karretch's causal loop/bootstrap paradox idea (after all, if time travel is still in its infancy, how come there's already a guide? Golly, I wonder who wrote it...) but now it seems like that couldn't possibly work out.