Lester del Rey - Pursuit

Wilbur Hawkes wakes with no memory of the last seven months. He knows he's in danger, but he doesn’t know why. No sooner does he leave his apartment than it explodes in flames, and, to escape, he must run through New York, not knowing where to run, or who he is running from.
With heat rays, disintegrating men, and exploding cats, how can this not involve aliens? What other explanation can there be?
— Summary by Dale Grothman