How about not simply summarising, but creating a broadly similar novel, with similar characters which undergo broadly similar story arcs?
I can see how it could end up as infringement, but also how one could avoid infringement. The issue would seem to be if the original author wishes to sue.
As an example, compare Brooks "The Sword of Shannara" with Tolkein's "Lord of the Rings". It is widely accepted that the former is heavily derivative for the latter; in my view essentially being an example of the above broadly similar novel.
Yet AFAIK, Tolkein's estate didn't sue Brooks. However if they had, how likely would a victory have been?
Now in the case of "Generative LLM", we may have an even closer "derivative work". However the LLM users could well get away with it if they consume a wide enough canon, and the source authors either do not learn of the derivation, or do not have the means to sue.
One of the key lessons learned in the past half-century is that lawsuits like that are:
(a) Often won
(b) Pyrrhic victories
Right now, it's the policy of Paramount not to sue over very clear violations of Star Trek copyrights (see: Star Trek Continues), Rowling to not do the same for Harry Potter (see: Methods of Rationality), etc.
A lawsuit like that results in a modest payout and take-down, together with a loss of brand worth many times that.
On the other hand, the derivative works tend to drive brand value, recognition, and sales.
That's why many works have clear guidelines supporting and encouraging derivative works, with specific boundaries to make sure they don't undermine those works.
I don't know The Sword of Shannara, but each time someone says "inspired by Tolkein" or "building on themes from," Tolkein increases in brand value as a classic and then THE classic. There is a legal line as to where inspiration becomes copying, but if we were to assume, arguendo, that it's clearly over that line, it still probably wouldn't make sense to sue. At best, that would have a chilling impact on more works in the "inspired by" category.
Yes.
> If I can paraphrase it, ditto.
Not necessarily. Summarizing, for instance, is typically free use.