Flashes of Panic

I was browsing course websites (I’m impatiently waiting for some of my professors to post book lists; the only one who has, isn’t assigning any,) and I happened by this semester’s Cryptography course, I noticed something weird about the text:

About the course: 20-5-12-3-15-13-5 20-15 3-18-25-16-20-15-7-18-1-16-8-25! 20-8-9-19 6-21-14 3-12-1-19-19 20-9-12-12 20-5-1-3-8 25-15-21 19-15-13-5 15-6 23-8-1-20 9-19 7-15-9-14-7 15-14 23-9-20-8 13-1-14-25 15-6 20-8-5 16-15-16-21-12-1-18 3-18-25-16-20-15-7-18-1-16-8-9-3 1-12-7-15-18-9-20-8-13-19. 4-5-19-16-9-20-5 20-8-5 6-15-18-13 15-6 20-8-9-19 20-5-12-3-15-13-5, 23-5 23-9-12-12 2-5 6-15-3-21-19-19-9-14-7 15-14 8-15-23 20-15 13-1-121-5 7-15-15-4 5-14-3-18-16-20-9-15-14 19-3-8-5-13-5-19, 14-15-20 8-15-23 20-15 2-18-5-1-11 2-1-4 15-14-5-19.

Yes, I worked it out. (Yes, there are errors in the ciphertext.)

Now Playing: Believe You Me from Some Friendly by The Charlatans