Explore "Inside Earth" by Poul Anderson on Textopian. Read with annotations and highlights.
The delay was partly due to the slowness with which I had to work, even after a plan had been laid. I could only do a little at a time, and the times had to be well separated. Each day brought the moment of onslaught closer, but I dared not hurry myself. If they caught me at my work, there would be an end of all things.
But I cannot swear that my own mind did not prompt me to an unnatural slowness and caution. I was only human, and every day was one more memory.