How do you parse this? "beyond description horrible", from Frankenstein

[Erin]

I have a feeling that Michael will be able to help me with this one. I'm reading Frankenstein, and I've come across this sentence, which has a construction with which I'm unfamiliar:

Sleep fled from my eyes; I wandered like an evil spirit, for I had committed deeds of mischief beyond description horrible, and more, much more (I persuaded myself) was yet behind.

Does horrible modify description? In other words, does this mean that his (Victor's) mischief would be considered worse than horrible?

[wasleys]

I hate to disappoint you. As I have often said here I don't do grammar, I just speak the language so I'm never quite sure what a modifier is.

However I think the answer is no. I suspect horrible applies to deeds of mischief. To paraphrase: "deeds of mischief which were too horrible to describe".

Does that make sense?

[Tino]

Sleep fled from my eyes; I wandered like an evil spirit, for I had committed deeds of mischief beyond description which were horrible, and more, much more (I persuaded myself) was yet behind.

It is a reduced adjective clause where the adjective clause connector (which) and the "be" verb (were) have been reduced leaving only the adjective. Usually we do not do that, we leave a phrase (this is called a participle modifying phrase), but in this case Shelly took liberties. The adjective clause "which were horrible" is modifying "deeds", yes.

The movie, which was very boring to most of us, lasted three hours.
The movie, very boring to most of us, lasted three hours.

Tino

[lubbles]

Deeds that are "beyond description" horrible. Beyond description describes the horribleness. How horrible were the deeds? Beyond description horrible. A similar but simpler sentence would be " deeds that are very horrible". Here we replace very with beyond description, to better describe the NATURE of the horribleness, or HOW horrible the deeds were.