Purple B 2002 MIT Mystery Hunt

THE PATH OF THE ARGO

"Hey, man, I think there are some sirens over on that rock, too!"
Each answer begins at the correspondingly numbered square, in the direction indicated, and makes one or more right-angle turns as it wends through the grid.

1E: Beethoven's only opera (7) 11S: Crucifixion setting (9)
2W: Strains (5) 12E: Source of rolling refreshment (6)
3E: Where cyclists cycle (9) 12S: Tree trimming (6)
4E: Dooley's school (5) 13S: Wide, as a chasm (7)
5N: Unable to find the right person (8) 14N: Red Hot Chili Peppers hit (9)
6S: Curtains (7) 15S: Owl, e.g. (6)
7N: In other words, in other words (5) 16S: Exactly (8)
8E: Trillers, frequently (8) 17N: Fair (10)
9E: You write notes on it (10) 18S: Gunpowder ingredient (5)
10N: Like Dudley Dursley (7) 19N: Like a saw (7)
10S: In the future (7) 20S: Knox blocks (6)
21W: She played Michael J. Fox's sister (11)